We’ve been finding a lot of small animal bones lately and they’ve been a great addition to our nature studies. I had a lot of people ask about our process to clean them, so I decided to document our most recent finds. For the purpose of this tutorial I’ll be starting with bones that are already free of flesh and soft tissue. The rodent bones in this tutorial were humanely collected and free of soft tissue for the most part when we found them. If you are working with a fresh specimen you will need to remove the soft tissue first. It’s best to let specimens naturally decompose, and the two methods I am most familiar with are maceration (soaking) and burying. They both can take several months and the more flesh you start with, the longer the specimen will take to prepare. I personally don’t have experience with preparing fresh specimens (it is also illegal to collect roadkill here in CA) so I won’t go into detail of how to carry out these methods. If you are interested, there is a lot of information online on these methods.
We’ll be using a highly concentrated hydrogen peroxide to clean and whiten the bones. Cleaning the bones with hydrogen peroxide will sanitize them and kill any harmful bacteria while also whitening them. We display our bones on Elliot’s nature shelves and also use them in our nature studies, so making sure that they are safe to handle is crucial for us. For the fastest results you can use a 20 or 30 percent concentration, but I’ve had great results using 40v hair developer which contains 12% hydrogen peroxide. It is essentially the same, easier to obtain and more affordable. Take care when working with concentrated hydrogen peroxide and keep out of reach of children and pets. Never use bleach on bones as it will damage the bone and in time the bone will start to yellow.
Notes on collecting specimens:
– Check your state regulations before collecting any specimens. Many states may require a permit to legally collect wildlife specimens. There are several legally restricted species that are protected by state and federal laws. It is also illegal to collect any endangered species in any state.
– Collect humanely and please be conscious of your impact on the environment when doing so. Do not collect in large quantities at a time and please don’t collect with intent to sell.
– Please do not kill living creatures to obtain specimens.
– Always use sanitary methods when collecting fresh specimens and/or bones and supervise children and pets at all times. Handle fresh skulls with disposable gloves to protect yourself against viruses.
Materials:
– a container large enough for your skull or bones
– something to cover the container
– 40v hair developer (12% hydrogen peroxide)
– old toothbrush
– dish soap
– rubber gloves
– animal skull or bones
Instructions for cleaning animal bones:
Step 1: How to clean and degrease animal bones
Fill a bowl with water and dish soap and use an old toothbrush to gently scrub and clean your bones. The cleaner the better. If you’re cleaning a skull, small teeth may fall out in the process. Just hang onto them and glue them back on at the end once everything is dry. Soak your bones in a new container of water and dish soap for 24 hours to degrease the bones. If there is a lot of grease that collects on the surface, change out the soapy water and do another round of degreasing until they are sufficiently de-greased. You’d be surprised at how much grease comes out of the bones!
Step 2: How to clean animal bones using hydrogen peroxide
The next morning, rinse your bones thoroughly and place them into a new bowl. Cover with a 50/50 mixture of hydrogen peroxide/hair developer and water. Make sure that the bones are fully submerged. Cover loosely with a lid and let sit for 24 hours.
After 24 hours, check on your bones and if you are happy with the whiteness, rinse thoroughly and let dry. If you’d like to soak them longer, change out the hydrogen peroxide mixture and check on them in another 24 hours. I’ve soaked bones up to 48 hours successfully. Keep in mind that they will dry a bit whiter than they look when they are wet.
Step 3: How to prepare bones for display
Let the bones dry completely. Use a small amount of white glue to glue any that have fallen out teeth back in, then display on your shelf!
Erica says
Can i use 3% hydrogen peroxide? Thanks x
Woodlark says
Hi Erica,
Yes, you can. I would dilute it less.
– Ashley
Nick says
Use it straight, don’t dilute. Better if you can get 6% peroxide. Using that straight is the same as using 12% and diluting 50:50
Woodlark says
Hi Nick,
Thanks for the input!
– Ashley
Chase says
Hi! Hairdresser here! I use Hydrogen Peroxide every day so I believe I’m qualified to say… this is entirely untrue. 12% diluted 50/50 is still going to be significantly stronger than undiluted 6%. I know 12% has twice percentage of 6% but 12% is actually 4-6 times stronger than 6%!
Woodlark says
Thank you Chase!
– Ashley
Bruno Costa says
Diluting 40v(12%) by 2, 50/50 will give you a 20v(6%), the 10v (3%) is still half as strong as the solution used in this Post. So you can use it straight, but will not be as strong. It’s basic Chemistry and Math.
Ian says
How would you best recommend repairing cracks in bones? I have two bison leg bones I had wanted to use for a knife handle, but after degreasing and letting them dry, both have long cracks running up the middle of one side. Thanks for all the useful info!
Ondrej Palous says
Hey Ian, in that case it would be wise to stabilize the bone with epoxide. The bone needs to be thoroughly degreased, at least the final wash should be done with acetone (I’ve got the best results this way so far). Epoxy resin needs to cure either in vacuum or under high pressure, in order for the resin to permeate the pores and cracks in the bone. If you are lacking the gear (vacuum pump or pressurized chamber of some kind), I am sure, that there is a company or workshop in your vincinity, that can help you out: try cabinetmakers, modelers or other knifemakers: they may do the epoxy job for you for a fee. Stabilising the bone this way is only guaranteed way how to safely use it for a knife handle/scales. You may be lucky and yield quite good results with a home kit vacuum chamber, or even sealed container and vacuum cleaner in conjunction with a low viscosity epoxy, but these methods are unreliable. I am sure that you can dig for more info about epoxy types and all the necessary gear on various net forums, bone stabilization is quite widespread thing in custom knifemaking business. I’ll try to summarize my rather chaotic text: If you gonna do just one knife, let a professional stabilize your buffalo bone. If you want to do more projects like this one, check the net for pressure chamber for resin casting, Amazon has got some neat kits from 100 to 250 USD… Good luck with your project, Ondrej
Jd says
I found a dead rat that has been sitting for about two weeks and hasn’t gotten picked up. Am I allowed to let it decompose for two more weeks then take the skull of it? I also live in California.
Woodlark says
Hi there, in terms of legality it is illegal to collect roadkill in CA and to legally collect (approved, since there are some restrictions of specimens that can never be collected) specimens here you need a SCP (scientific collecting permit).
– Ashley
Jd says
So it would be illegal to take anything from the rat? Okay, then where and how would I be able to get a SCP to potentially collect from other specimens?
Woodlark says
You can submit and application for a SCP through the wildlife.ca.gov website. Unfortunately the rules are quite strict here in California and can be a bit tricky to sift through. I wouldn’t be able to give you a definite answer because it really depends on specific factors including where the specimen is located and the exact species you are attempting to collect. Generally speaking, a common rat should not fall under the “roadkill” category and is not an endangered species so then you’d need to consider any other possible factors. When it comes to collecting specimens I do of course advise doing so legally and ethically and remembering to never collect from protected areas (such as national/state parks or reserves) or mess with endangered species.
– Ashley
Carrie says
That’s all so crazy to think about. I live in Kansas and I’m pretty sure they almost encourage you to take roadkill. I would never have even thought twice about taking an animal bone that was just on the ground. I don’t really know how I feel about all of it because I’ve literally never thought about it before.
Woodlark says
Yes! Rules and regulations vary so drastically from state to state. That’s really interesting to hear about what it’s like where you live, thank you for sharing!
– Ashley
Taylor says
Hi I found a bone that seems to have been fossilized and is rather porous. Is this the most effective method for that type of bone? I am worried about putting it in water. Thanks! (I’m from WA btw and my collection was totally legal)
Woodlark says
Hi Taylor! If the bone appears to be very porous it could also be brittle/delicate and I probably would not recommend doing a soak for any length of time just to be safe. Depending on the condition of it you may be able to do a quick gentle scrub with soapy water and a soft brush.
Ashley
Taylor says
Awesome thank you!!
Woodlark says
You’re so welcome! Good luck and enjoy!
Ashley
Myco says
I have some fairly clean bones I (legally) collected from the side of the road. A friend recommended using “bone cleaning powder” to kill anything nasty living in the marrow, but I’m not finding any results for that, aside from maybe “biological washing powder.” What is my friend talking about here? Is this covered by the dish soap and peroxide steps, or is this an additional step for safety?
Woodlark says
Hi there,
I have not heard of “bone cleaning powder” so I’m not sure exactly what your friend is referring to. I have heard of people using “washing powder” to clean bones but I have not personally used it. The dish soap/peroxide method outlined here is a complete process to clean and disinfect so your bones would not require additional cleaning if you opt to use this method. There are instances where I would not recommend doing a peroxide soak (i.e. very old and brittle bones that could potentially be damaged during the process) but if your bones don’t seem to be old and fragile you should be good to go.
Ashley
Myco says
Okay, that’s what I thought, just wanted to make sure I wasn’t missing something! Thank you!
Woodlark says
Good luck! Don’t hesitate to reach out if you have any other questions. Happy to help!
– Ashley
Brett says
There is an additional “first” step if there is still a bit of tissue on the scull. Same technique as the soap and peroxide but start with “cold water” laundry detergent. It has enzymes that will eat away at any soft tissue, then soap to degrease, then hp to whiten.
Sunshine says
I have a skull that has been sitting long enough it has no matter at all connected to it- its probably been sitting at least 6 months in our field. I don’t want to whiten it at all, I’d honestly rather leave it as natural as possible but I do want to be safe and sanitary so I don’t have to worry about handling or it being around my pets.
What are my options? Is the safest method still the one above or could I just use a cleaning agent (rubbing alcohol or grocery store hydrogen peroxide) i don’t want to brittle the bones at all or very little if possible 🙂
Thank you!!
Woodlark says
Hi there,
I have not personally used isopropyl alcohol to disinfect bones but in my opinion a diluted hydrogen peroxide soak would be the best option. You can use hydrogen peroxide that you purchase at the grocery store– it will just be a lower % so I would also dilute it less than the instructions above for the hair developer. Since you only want to sterilize them without whitening them I would just leave them in the diluted peroxide for a very short period of time, maybe 1-2 hours. Good luck!
– Ashley
Alissa says
Hi! I love this article and am wanting to clean the bones of my first dog. I found that there is 40v creme developer and CLEAR developer. From my understanding…
“The type of chemical ingredients used to make both products differ. Creme developer is oily in addition to including other ingredients such as glycerin, conditioning wheat germ protein or cetearyl alcohol. On the other hand, peroxide or clear developer mainly contains de-ionized water and hydrogen peroxide.”
However, I haven’t seen any bone cleaning articles that mention this clear developer. I’m wondering if it’s good or bad to add oils back to the bones after decreasing. Does it defeat the purpose or help?
As for long term care, do bones in an indoor display need any maintenance to keep them from becoming brittle?
Woodlark says
Hi Alissa!
I’ve used both creme and clear developer. Clear developer is the better option if you just need to soak the bones. The extra ingredients in the creme are not necessary but the thick consistency of creme developer does allow you to use it as a paste which may be helpful depending on the bones that you are cleaning. The clear is a liquid consistency since it is basically just hydrogen peroxide. I use whatever I have on hand or have access to at the moment, but my choice between the two would be the clear.
Bones should just be stored in a place that is cool and dry and they need to be 100% dry if you plan to enclose them in something completely. Also it’s important that you don’t store them somewhere that the humidity levels will fluctuate a lot. We store our bones in specimen jars as well as inside of a wood collection box. Good luck!
– Ashley
Leo says
May I ask where you go this shelf?? I love it! Thanks!!
Woodlark says
Hi Leo,
Yes! It’s an old printer’s tray. Just a note that– these trays often have a high lead content since letterpress letters were made of lead, so you may want to test it before if that’s a concern for you.
– Ashley
Ame stevens says
I have collected a lot of bones in the past few months of varying sizes, clean-ness, and type. For the last week, any and all that don’t seem clean from being outside for years, I have covered with salt, hoping that will kill any immediate bacteria.
At the moment I only have isopropyl alcohol, 3% hydrogen peroxide, and 20vol hair developer. Would any/all of these actually clean the bones or should I try and get something else?
Woodlark says
Hi Ame,
You can use the same instructions with the 20v hair developer and soak for longer if necessary.
– Ashley
Sarah Smith says
I found a jaw bone of what looks to be a jaw bone that belonged to an outside cat that belonged to my family. We have a big family of cats outside and it’s been around for many cat generations. I didn’t think about it then but I grabbed it and played it in a plastic bag. Sprayed the bag with Lysol and put it away. I washed my hands of course. The flesh was all gone from the bone. Just brown dry spots. Am I safe from catching anything from it? I figured it the flesh was gone, I was safe.
Woodlark says
Hi Sarah,
It sounds like the bones were there for a while if they did not have any remaining flesh on them. The method outlined in this post would work well to sanitize and clean the jaw bone if you’d like to keep and/or display it. Enjoy!
– Ashley
Victoria Smith says
What should I do with the remaining water/ other liquids? Is it safe to throw it away?
Woodlark says
Hi Victoria,
Yes, you can wash the water and hydrogen peroxide mixture down the drain. If there was any fur or debris from when you did the initial cleaning I would screen out and dispose of those first.
– Ashley
Parker says
Hello I found a bone I’m pretty sure is a pelican vertebrae (found in the ocean) pretty sure it’s legal to take, because bird bones are spongey, do you think i can use the same method?
Woodlark says
Hi Parker,
As far as I know, pelicans are migratory birds which are protected in the US/Canada under the Migratory Bird Act. This method can be used for more porous bones but be aware of the soak time and they will become more brittle than others.
– Ashley
Nada says
How would you go about cleaning a cow skull?
I had no choice but to bury it in the garden to let the bugs eat the remaining flesh/brain as I had no access to any of my usual resourses for a skull that large. (Even at my uni where we dealt a lot with bones of farm animals, cleaning a skull of that size might have been a problem)
After digging it up, all the tissue is gone, but the skull itself got some sort of plaque on it. I was able to wash it to bone-white in some places, but the places that have the plaque are impossible to clean with just water and soap/detergent.
I cannot really submerge it in anything as the only container big enough is my bathtub (and you’d need a LOT of peroxide for that, not to mention having to live in the small apartment for 24 hours with a bath full of basically bleach)
I thought of maybe using a stronger bleach solution and applying it to rags to “bandage” the skull with, or just scrubbing with bleach maybe?
I really have no idea what is it with that “plaque”thing as I have buried bones before several times and none of them had it. It’s sort of a rough porous texture and light grey in colour.
Woodlark says
Hi Nada,
It’s difficult without seeing the skull but I think the method outlined in the post is perfect for your needs (using the hair developer since it is paste-like and you’ll be able to rub it on and let it sit). I *do not* ever recommend using actual bleach because it will damage the bones long term. The hair developer contains hydrogen peroxide, which is what you’ll want to use. You can use the bandage method that you mentioned on top of the paste and I would do it somewhere outdoors where animals etc, won’t be able to get to it. You may have to do several rounds of it over a few days. I’m unsure of what the “plaque” that you are describing may be, but since you mentioned that it was porous compared to the rest of the skull it may be some sort of degradation to the bone in those specific areas.
– Ashley
Dan Giampaolo says
I would like to use Beef Marrow Canoes as a serving plate and keep reusing them. Will your method prevent ant food poisoning in this process?
Woodlark says
Hi Dan,
I don’t recommend using this method for something that you will consume food on. My *guess* would be that boiling may be a good option but I’m unsure. Good luck!
– Ashley
mali says
hello! i collected an already deceased rabbit from my front yard a few months back in september. i just today rinsed the mush that was left with a garden hose and placed the larger bones as well as the skull on a baking tray with foil. obviously i don’t intend to bake them, but is there a specific amount of time i should wait before doing something? the bones are disconnected from the body. also, if you have any tips on removing bones without the smell… please let me know.
Woodlark says
Hi Mali,
If there is any remaining flesh on the bones I’d recommend burying them first for a bit, then following the process outlined in the post to degrease then clean the bones. Good luck!
– Ashley
Casey says
Is there anything I can use other than hydrogen peroxide? Would it be possible to use something like OxyClean? Thanks!
Woodlark says
Hi Casey,
I have heard of people using oxyclean successfully but I do not have any personal experience with it so I’m unsure of the proper ratios, etc. Good luck!
– Ashley
B says
Was just wondering, is there anyway of using these method(s) without the teeth etc falling out please?
Woodlark says
Hi, teeth usually do fall out during the cleaning process. You can glue them back in afterwards if you’d like.
– Ashley
Kallie says
Hi! I found a decomposing squirrel near the woods (in MA) and finally the bones are showing. I managed to grab and clean the skull as well as a femur. I found the lower jaw separated but it still has hair on it:/ how do I remove the hair???
Woodlark says
Hi Kallie,
For the remaining flesh on the bones I’d recommend burying the lower jaw for a bit to let it naturally decompose.
– Ashley
Cassie says
I found an old horse skull years ago. (at least 10 years) I decided I was going to try to preserve it as much as possible, its a little cracked and chipping in places and also has moss growing on it. I was wondering if I use the same method or something different?
LeRoy Haglund says
I have recently had a hip replacement I would like to know how to preserve the head of my femur to incorporate it into a cane or walking stick any advice would greatly be appreciated. Thank you, LeRoy,
Nick McKenna says
Wash in warm soapy water, rinse clean.
Soak in 6% hydrogen peroxide to bleach and sterilize. – Few hours, up to 24hrs. Depending on desired whiteness.
Allow to dry properly, then glue onto walking stick in desired manner with expoxy glue.
Seal with several coats of polyurethane timber sealer or shellac. Tint may be added to this if colour is desired.
LeRoy Haglund says
Thank you
Carly says
Does anyone have any advice on how to turn a deer rib into a hairpin?
I’ve had this deer rib bone in my closet for a long time. Recently I saw someone on Tiktok who turned their deer rib into a hairpin. Would this method still work for a deer rib? Would I be able to sand it safely afterward to make it smooth or will that be unnecessary? Thank you for any advice you may have! 🙂
Ivy says
Hi! Just came across this page. When you say to use peroxide, I was wondering two things; if the chemical smell lingers or if there is another chemical-free way to clean and sanitize bones. I have a chemical intolerance, so with a respirator I’d probably be fine while using the peroxide but often I can still smell any chemical that typically would have “lost” it’s scent. For example, I had my hair dyed professionally and six months later the ammonia smell was still bothering me. So, maybe instead of risking not being able to admire my bones because of the smell, if there is another method I could use. I’ve heard boiling isn’t great as it softens the bones, but if I’m just displaying them…fragility shouldn’t be a huge issue right?
Woodlark says
Hi, if you’d like to just remove the flesh off the bones you can use the burying method. It will take quite some times and the bones won’t be very white but eventually they will be free of flesh and such. You can boil the bones to sanitize them– you’ll just need to be very careful to not overboil them. Overboiling them will cause them to fall apart.
– Ashley
Wren says
Hi! I washed a jaw bone i had found in soapy water, and it appears to have turned a lot more green than it was when i found it. Why is that and how can i fix it? Im new to this whole thing. Thank you!
Woodlark says
Hi Wren,
Have you tried the hydrogen peroxide soak? I would also try leaving it out in sunlight for a little bit and see if that helps.
– Ashley
Pepper Crowley says
Hey there! I have a frog skeleton that is entirely intact. I believe that all of the soft tissue is gone except for whatever is holding it together. How would you suggest that I clean it in a way that would keep it together?
Woodlark says
Hi Pepper,
If the bones are being held together I’d assume there’s residual cartilage present (skeletons are held together by cartilage) which is a soft tissue. If you’d still like to clean and preserve it now, I’d recommend taking photos and making notes of how the bones fit together so that you can piece it back together afterwards.
– Ashley
Pepper Crowley says
Thanks 🙂 I’ve taken note of it’s anatomy, and am giving him a good long soak to separate whatever cartilage is left. Is there a particular glue that you could recommend to put skeletons back together? I imagine some glues would probably damage bones, especially really little ones. Thanks again, Ashley!
Woodlark says
Hi Pepper,
Plain Elmer’s glue is always a good option– it’s safe to use and is water soluble in case you make a mistake. It works especially well for really small bones like teeth.
– Ashley
Ankhasha says
This thread has been so helpful! I have come across some bones that have been outside for quite some time (all the flesh is gone and it relatively white and looks a bit porous in parts. Would you recommend the de-greasing step still? Many thanks!
Woodlark says
Hi Ankhasha,
I would still do a quick soak to be sure but wouldn’t fuss over it!
– Ashley
Nick says
Hi, I want to decorate my plant pots with rodent bones. My main concern is that if I use hydrogen peroxide, the bones will absorb it and whenever I water my plants, I end up washing the peroxide into the soil – Would that happen, and if so are there any other cleaning solutions I can use?
Woodlark says
Hi Nick,
If you’re mainly interested in just removing any flesh or remnants from bones (and not concerned with whitening) then you can just bury them in soil until no soft tissue remains.
– Ashley
Nick says
Hi Ashley, is soap and water enough to sanitise the bones then? I wasnt sure if peroxide was a must for that
Kaethys says
I have a bird’s skull with a black beak in the freezer. Will the beak be bleached if I use this method? How can I keep the beak black?
Thanks in advance
Woodlark says
Hi Kaethys,
I would probably prop it up in the hydrogen peroxide mixture so that the beak is not submerged. Good luck!
– Ashley
Elizabeth Maurno says
I followed these steps for some chicken bones I have and the joint areas of the bones seem to remain really soft(no tissue left). I tried to shave off the softness until I realized it was more than just cartilage but part of the actual bone. Anyone have any ideas on how to fix this? I’m doing one more bleaching with 40V hair developer and then plan to let the dry after that.
If I leave them to dry for a longer period of time will they harden up?
Carl says
Hi and thanks for giving your info and knowledge so freely. I have some whale bones, a few vertebrae, a couple of ribs and a super spectacular tail fan bone. I bought these a few months ago from locals here in Costa Rica who fished them out of a small bay where the whale’s remains had washed up. This had to be a whale that died of old age at full growth because these things are massive!
These things STUNK to high heaven when I got them you could smell fermenting whale oil from like 10 feet away. My instinct was to let them dry in the sun, and as they did, the oil came out through the porous bone and formed black tar-ish looking deposits, but the smell had almost gone. Today I washed the bones carefully with a small pressure washer and got most of the black off, and have them soaking in a makeshift wood and plastic sheeting tub in solution of detergent and de-greaser.
I have an idea to try a technique for the peroxide/soap that will prevent me from having to buy 50 gallons of Hydrogen Peroxide, which is hard to find here in CR. I was thinking of putting the bones one by one in industrial plastic garbage bags, putting in a gallon or so of soap/water/peroxide solution. then using a shop vac to form a vacuum between the bag and the bone, drawing the solution up to tightly surround the bone, rotating it’s position every 1/2 hour or so. What do you think of that idea? Thanks.
Bobby says
I have a large whale vertebra that I bleached and now after 5 years it is a bit crumbly. Is there a way to seal it to stop it from crumbling?
Woodlark says
Hi Bobby,
Unfortunately when you use bleach the bones do degrade quickly as you’re experiencing now. I’m not sure that theres a way to stop the process.
– Ashley
Ivy says
Probably not a comment you thought you’d get, but thank you. I’m a writer and I’m doing research. I have a town that hosts a major ossuary and this was super helpful insight to the logistics of that. No intention on touching any bones myself, but I now know what to have my characters do. Thank you. (This was also a breath of fresh air after I found an AI article that tried to tell me that healthy bones should be green because “green in the color of life and health” …Yikes.)
martyna says
hi! I’ve never collected bones but this is really useful! do you have any tips for people how are just starting?