Skull Cleaning 101

Cleaning skulls. Oh, what a topic! I’ve gone back and forth in my head a million times – is this something I should blog about? It’s one of my favorite hobbies, something I pride myself on knowing a lot about, and I definitely feel that I have information worth sharing but it’s a sensitive topic for a variety of reasons. Blogging about it I run the risk of scaring away readers who are offended, grossed out or simply just not interested. But like I mentioned above I have information I want to share. When I first started this hobby I had the hardest time finding answers to my questions. Even as a beginner there was a lot I read that I immediately could see was misinformation. I’ve learned so much just by trial and error.

I am an extremely visual person. I can gather more information from one photo than I can from a few paragraphs but because this can be such a graphic process I will not be sharing any photos of unfinished skulls. This just isn’t the place. I will share as much detail as possible though so if this isn’t your cup of tea, I suggest you scroll on right now. I’ll be back with your regularly scheduled programming tomorrow.

Obtaining skulls.
There are lots of different places to get skulls. My two main sources of skulls are the woods, I find them on hikes, and my dad’s friend from work. He hunts, and has no use for the heads so he sends them my way.  Mickey, my good friend who is a taxidermist, recently wrote post on ethical taxidermy and how the term varies greatly because ethics are subjective. It’s an important read and it’s important for you to decide for yourself what is okay. I would never kill for my collection, and I certainly hope you wouldn’t either but being able to use a part of animal that someone else would otherwise just throw away is perfectly fine by me.

The best way I can recommend to get skulls is to let people know to keep their eyes open for you. Put out feelers. People won’t know to give you skulls unless they know you’re interested!

Just a reminder that, in most states picking up roadkill is illegal without a permit, so do your research if that’s a route you’d like to take! And if you’re in the US – stop picking up bird skulls. Bird law is real.

Gather your supplies.
I have a locker in my dads garage filled with my supplies, inside are…
▴ Gloves. Elbow length & regular disposable rubber ones.
Heavy duty vinyl apron. You don’t want to splash anything on yourself, believe me.
Respirator. Maceration is very smelly process, more on this below.
Scalpel handle and blades.
Field instrument kit. You don’t actually need everything in this kit but I’ve found it incredibly helpful!
Bucket with lid. The container some kitty litters come in works too!
Peroxide. Not bleach. Never bleach.
▴ Small container only slightly larger than the skull you’re working on.
White Elmer’s Glue.

It’s always a good idea to have an extra pair of gloves and a few plastic bags in your car or camera bag if you’re hoping to find skulls while you’re out and about. Nothing worse than finding a great specimen and having no way to transport it.

There are lots of different ways to clean a skull. My method of choice is maceration. I simply skin the skull. (There are tons of tutorials online on skinning, it does take a bit of practice.) Then plop it in a bucket full of water. The bacteria eats away the flesh and after a period of time you’re left with a clean or mostly clean skull with fairly minimal work.

Hair is not broken down by maceration so you’ll be saving yourself lots of time by skinning the skull first. You’ll also want to remove eyeballs which is where the field instrument kit from above will come in handy.

I like maceration because it works well on animals in all different stages of decomposition. It’s obviously best on “fresh” flesh, the bacteria will flourish. Even with skulls that have dried or mummified flesh on them soaking them in the bucket will loosen anything so it’s easily removed. Another up side to maceration is that everything is contained so there’s no worry of another animal running off with your skull or losing any pieces during the cleaning process. The downsides are that is smells REALLY bad and it can take a while.

Most people you who use maceration as their cleaning technique keep their water at a constant temperature using an incubator or aquarium thermostat. Keeping the water warm helps provide the bacteria with a great habitat to live, and multiply. I actually don’t use any sort of water heating though. Simply because I don’t mind if it takes longer.

How long maceration takes really depends on the temperatures, and how large the animal is. I would say on average it takes 3-4 months for a skull to be finished without regulating the temperature.  It’s a good idea to change your water at some point during the period if it gets particularly nasty.

Let me just reiterate one more time – maceration stinks. It’s probably one of the worst smells you’ll ever smell. Do not do it in your house, and don’t do it if you have a very small yard. Wear a respirator and if a friend is kind enough to let you do it on their large piece of property bring spare clothes because you’ll probably smell afterwards.

Maceration tips.
▴ Be patient. Maceration takes time, especially if you’re not regulating your temperature. I process skulls at my parents house since they live on seven acres. If I’m feeling particularly impatient I will take them out and do a little bit of work with my field kit, cutting off any flesh I can just to speed up the process. Wear your respirator if you do this, please!
▴ It’s a good idea to wrap skulls in cheesecloth or even old pantyhose before putting them in water. You want the liquefied tissue to be able to leak out yet you don’t want to lose the little pieces, like teeth.
▴ Don’t forget about your skulls. When you first start out the excitement will make it really really hard to forget about skulls you have soaking but after some time it is kind of easy to forget if you have anything processing or not. If left in water too long skulls can become weak, and brittle.

Whitening + Finishing Up.
After macerating you may need to do some finishing touches such as removing connective tissue. Use your field kit to remove any remaining tissue. EVERY SINGLE PIECE. Anything, I mean anything, left will start to smell eventually. Take your time looking over the skull and making sure there is nothing but bone. Gently hose down the skull, I wouldn’t recommend bringing it in the house at this time. It will most likely have a stench to it still.

Find a container only slighter larger than the skull you’re working with, fill it with peroxide and add the skull. Never ever ever use bleach. I don’t care who told you or where you read it was okay but it is not. Bleach ruins skulls. I don’t cover my skulls once they’re in the peroxide and I do leave them outside. The sun will help speed up the process. Depending on the size of the skull and the condition it’s in it shouldn’t take too long at all for it to whiten. Generally I’d say it takes three to four days, sometimes less and sometimes more.

After the peroxide bath I bring the skull inside, rinse it off then wash it with dish soap, rise again and set it on a wash cloth to dry. After they dry I start putting everything back together. Regular old Elmer’s Glue is what I use to glue the mandible back together and the teeth back in.

To glue the mandible back together I simply put glue on one side and squish the two pieces together. I set them down on a table, still holding them together, and place the skull on top making sure they fit together perfectly. If they do you should be able to leave the skull on top of the mandible while it dries. Just be careful not to bump it for the next twelve hours or so. Sometimes it’s a pain, and takes a bit of fiddling around before you can get them to balance perfectly.

skull collection, skulls, skull cleaning guide

This + That. 
▴ I recommend the book Animal Skulls : A Guide to North American Species. It is a must have if you’re cleaning skulls. It’s a little bit pricey, even used but it’s so worth it. It has photos, measurements, and tons of information to help to correctly identify skulls. My favorite part are the life size illustrations of skulls.
▴ Sometimes I get comments wanting to know how I get skulls to look so nice, or so white and on top of all the information that I shared above it really depends on your specimen. Below are two cat skulls I have in my collection. The one on the left was found on the side of the tracks. Nature had already done the dirty work for me. The cat on the right was cleaned from start to finish by me. Other than just the nasal bone and a few teeth missing the skull on the right is a lot more weathered. No matter how long I soaked it or whatever, it would never ever look like the skull on the right. Generally speaking, skulls you clean yourself will be of higher quality than what you can find already cleaned.

This is obviously not an all encompassing post on skull cleaning. Like I said, there are lots of different ways, this is simply how I choose to do mine. I recommend doing as much reading on the subject as possible. Take pieces of information from many sources to find exactly what works for you. Just remember; don’t bleach and don’t boil! Good luck! If you have any questions, let me know!


Author: Kaylah

Just a green haired gal from Cleveland, Ohio.

Leave a Comment

Your email address will not be published. Required fields are marked *


  • I love that you posted this! It's genuine and it's a passion of yours, so you should be sharing it on your blog if you so wish! My husband is a bow hunter and he's hoping to get an elk or a moose this fall, so I'll definitely be sharing this post with him when it comes time to clean up the animal skull. Thanks!

    • Thanks Ashley!

      That's neat! My brother is a bow hunter too, but just for deer – we don't have elk or moose here. (I soooo wish we did, I'd love to see one!) Do you eat those? Seems like you'd be able to eat on one for a long time!

  • This is a great post, Kaylah. Personally I only collect naturally cleaned specimens, but that's mostly because standing water is a no no in the outdoors here (mosquito breeding), and I don't have any indoor options. And you're right – nothing I have is so bright a white! Also Obtaining skulls from someone who hunts for food seems like an excellent choice to me… nothing is wasted!

    • Thanks Kelly!

      Wait – mosquitos aren't an issue if the water is covered though, right? You'd DEFINITELY want to cover the bucket, perhaps I didn't specify that clearly enough? I'm not the best at explaining things. Posts like this take me forever to write and still some how end up leaving out key information! 😛

    • Oh! DUH! Lol the guide I had read said water warmed by the sun worked well and I was like oh ok so open…? But obviously that just meant put the container somewhere sunny… no wonder my frog skeleton didn't work out. My one and only attempt with a cuban treefrog, I left the container open and the frog wasn't there in the morning!

    • You know what, I'm not 100% positive but I don't think that maceration works on frogs and other little things like that. The bones are just too tiny and fragile.

    • I really couldn't find a lot of information on it. The best I could figure from a lot of googling was that I could try it and it might work, but I might just end up with a pile of little bones. My goal if that happened was to arrange and mount them on a board of some kind but…. fail. I'll stick to admiring the work of the pros. 🙂

  • Oh my gosh! I'm so excited that you shared this!!! I have a small collection of skulls that I've come across "nature cleaned", but there have been so many times that I've come across fresh ones and just didn't have the space or equipment to do anything with. I love that you shared an equipment list! Now that I know exactly what I need I'll be adding them to my wish list!

    I love the comparison of the kitty skulls too-that's so cool!

    • So glad to be able to help, Mindi!

      I'm really glad you appreciated the kitty skull photo. When I thought of taking a comparison photo and realized I had the perfect skulls I was SO excited. I feel like is a great illustration of the difference between nature cleaned skulls and ones you have to do yourself.

    • I'm not sure. I really do love all of them in my collection but I am particularly intrigued by the beaver. It's just such a solid skull. I didn't realize how large and strong beavers were.

  • I'm fascinated by this process! I have kind of a gruesome question for you: Do you plan to do this with your own pets? My beloved cat will probably not live too much longer, and I was going to cremate her, but I think having her skull would be a much better memorial. I don't think I could do it myself, though 🙁 (Sorry if that was too gross, given the post I thought you'd not be too bothered, but I misjudge sometimes!)

    • I'm not 100% sure honestly. As someone who saves all the whiskers I find of theirs I, of course, would love to have their skulls after they pass but seriously I don't even like to think about them dying. The thought alone makes me all teary eyed. I don't think I could clean them myself but I would consider letting someone I trust do it for me.

    • Yeah, that's how I am too. I think I would just break down trying to clean them. Sorry for bringing up sad things! I want to have this planned out so I'm not caught off guard. Now I just need to search for someone I trust….

    • Be sure to keep a close eye on older skulls that you've found already cleaned outside, they're a lot more fragile than a newer skull and prolonged exposure to the peroxide could damage them.

  • I really like that you shared this! Personally, I'm not interested in doing that but admire people like you and this hobby, it's fascinating 🙂 Didn't know that it takes so long to get it done, good job!

  • This is absolutely wonderful! I sometimes get overwhelmed knowing what book to pick up to begin a new skill (especially if I have no one around me I can use as a mentor.) It's really, really nice to have a sort of "what to expect" snapshot of the process for those of us who WANT to do these things, but are sorta baffled as to where to start.

    I have continuous admiration for your ability to self-teach! So rad.

  • While I have almost zero interest in this… I actually found myself reading the whole thing. And sharing my knowledge, whether my friend wanted to know or not. Lol. I love it when people are passionate and it shows. You should be very proud of that. As well as an ability to write so well you draw a reader in.

  • Really great post! I love seeing any of your blog posts about skulls and teeth and your other interesting collections, they all really fascinate me and I can definitely relate to some. Glad to see you branching out a little bit with this 🙂 Just out of curiosity, what do you do with the waste you get after soaking the skulls?

  • I'm so excited for this post! I bought Animal Skulls: A Guide to North American Species based off of a past post that you did, and it's a very big help! It's not easy to find skulls or animals where I live, but I dream of someday really going out and searching. This post is definitely adding fuel to that fire :p

  • I love skulls, but as a vegan I don't think I could ethically buy any skulls commercially, mostly because of the points brought up by that article you linked. You just don't know! I found this really interesting, and I am debating if I should prep and buy some of tools you suggested just in "case" but uh… I am not sure how my parents would feel about me leaving a decaying skull in their backyard. XD My biggest concern would be their dog. Do you leave the lid on the bucket? Do you need air flow or light for the bacteria?