Introduction

So you're interested in decomposing your own critters for bones? This process can be time consuming and take some experience, but once you understand what is necessary it is not that hard at all. The most imporant things you will need are space and time.

Consider your climate. The best time to decompose animals is when the weather is not too cold or hot, there is decent rainfall, and good bug activity. For someone in a temperate climate (like me in the midwest), the best time is between spring and early fall. There needs to be plenty of flies and bugs to eat away at that soft tissue. If it is too hot or too cold, bug activity may be sparse and your body could end up mummifying. However this isn't the worst thing. If you want to read more about cleaning a mummified body via masceration (water decomposing), then visit Seti's page here.

Consider where you will leave your critter to decompose. Small animals need a month or two to decompose fully if the weather is perfect. If you have your own yard, this is the best place to leave your critter. If not, you may be able to find a spot in the local woods. Do be conscious of private property or state parks. I'm all for doing whatever you want as long as you don't get caught. It's not illegal to decompose critters, but it's not a fun conversation to have with suspicious people. Make sure there is very little human traffic in whatever area you use to avoid disturbing others. Unfortunately, this hobby is best suited for more rural areas, but if you get creative (and careful) you might be able to find a private spot in a park or local garden in the city.

Lots of people are concerned about the smell of decay, but I find that if your critter is outside and buried in a thin blanket of leaf litter, this reduces the smell almost completely. You will only smell it if you are within a few feet of it, and sometimes if the wind carries the smell. But for small animals, I almost never notice it.

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Collecting

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When collecting critters to decompose, you will have to get used to some gross things. If you're interested in this hobby then you probably already have an appreciation for death, but it's always good to know what you are getting into.

I get almost all my bones from roadkill, but some were killed by my friends' pets, and some I have found naturally in the woods. All of these animals are sad to witness, and come with lots of natural but gross bodily processes, such as blood from the mouth or wounds, broken bones, and purging (when an animal drains its bladder after it dies). Sometimes the eyes of roadkill animals will be bulging or look popped, which is the hardest thing to me (I'm saying all this because it's easier to read than to see first-hand. If you think you can handle it, then proceed!).

When you come across a dead critter, it's important to establish how far along it is in the decaying process. Consider what you are willing to touch, put in your car, and wrap up for decomposition. Do you have a weak stomach? You might only want to collect animals that have just died. Does a little blood and active decay not bother you? Feel free to collect things that look a little rougher.

Saying that, an animal that has just died is the best case scenario. These will still be limp with flexible limbs, they should not smell too much, and bug activity will be low. An animal that has been dead for several hours will be stiff, smell stronger, and have bug activity, though they can still be collected. If an animal smells very bad, and has a lot of bug activity (and sometimes you can see active decay on the surface), this may be best left to nature.

To collect your critter, use the dog poop technique. Take a plastic bag and put your hand inside like a glove, and pick it up with the bag so it stays inside and doesn't touch your skin. It's very unlikely for you to get sick just by touching a dead animal, but it's always a good idea to reduce the spread of germs. Tie the bag closed and double bag it to be safe. You don't want any liquids escaping and getting on you or your car! Making sure the bag is tied tight will also keep any flies and bugs trapped inside until you open the bag again. I sometimes keep a plastic box in my trunk to put critters in for extra protection.

Once you get your critter home or to whatever location you are going to leave the body, it's time to wrap it for decomposition.

Decomposing

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The most important part of this step is to contain the bones while the body decomposes, and to keep it from being stolen or scaveneged by other animals. This step is also the first time you will have to purchase materials out of an otherwise pretty cheap process.

I always wrap my critters in two layers--a fine layer of mesh to contain even the smallest bones, and a larger plastic garden fencing to protect it from weather and animals.

For my fine mesh, I use cheap hobby store tulle. It has very small holes so bugs can get in, but bones can't get out. The tulle mainly keeps the fur contained, which keeps all the bones inside. I will buy 2-3 yards and cut off pieces as big as whatever critter I have. It can be reused as many times as it lasts. Even if it gets a few holes in it, it can still be reused.

^{Honeysuckle the possum wrapped in tulle.}

I used to tie the tulle closed with a bagtie, but I've found that as long as the tulle covers the whole animal, the plastic fence will keep it in place. Leaving the tulle open might also speed up decomposition because it makes it even easier for bugs to find their way in.

For the outside, I cut a length of plastic hexagon garden fence to wrap around the critter. You can get this in a roll of several yards at lawn and garden stores and it will run you around $20. You should only have to buy this once, since it can be reused again and again. This fence is sturdy and rigid, and the holes are big but not big enough for little raccoon or possum hands to get into. Living animals will be attracted to the scent of death and will try to eat a fresh body, but they will give up if you make it hard enough. You may be able to find other things that work as your protective layer like chicken wire, but I find the plastic fence to be the easiest to work with.

^{Honeysuckle wrapped in tulle and plastic fence.}

I place the critter in the center of the fencing and wrap either side over. Using bagties from the grocery store, I tie both ends closed and put a few over the top for good measure. I usually use at least three bagties on either end. The tighter your fence is closed, the harder time living animals will have getting into it.

That's all there is to the wrapping process! Now you just need to leave your critter somewhere. I use a small section of my garden where tulips and peonies grow, and I've noticed the flowers grow back bigger and beautiful each year from the nutrients of the decomposing critters. I use a pitchfork to scrape up the leaves on the ground and lay the critter there, pushing the leaves back on top.

It's best for the critter to be touching the ground itself. This helps retain moisture and heat. The layer of leaves on top encourages bug activity and reduces the smell of decay.

Now all you have to do is wait! For small animals, I recommend checking back in a month during perfect conditions. It may take up to three months before you feel ready to clean your bones. However, don't let your critter sit for too long. The fats in the marrow and natural decomposition processes will eat away at the bones overtime, so it's best to have your critter cleaned within the year to avoid damage to the bones.

Here is Honeysuckle after decomposing for 5 months. I collected him in May, and here he is in October. He was a big possum, so it took a little longer for bug activity to cease completely.

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Cleaning

After a month or so, inspect your critter while still in its wrapping. If you see a lot of bug activity, especially multiple maggots feeding, or the body still smells of decay, your critter might need some more time on the ground. If you see the dry brown shells of maggots but no live bug activity, your critter is ready. It should not smell at this stage. There may be some bugs here and there, but as long as there are no maggots, it is good to clean. Maggots = soft tissue. They will leave once there is nothing left to eat on the bones.

There are 3 stages of cleaning: the initial brush clean, degreasing, and whitening.

Initial clean with water and brushes

Once your bones are free from soft tissue, you can now start the cleaning process. The goal of this step is to remove dirt and fur from the bones, so when you begin degreasing and whitening, there will be as little debris in your liquid solutions as possible.

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Dry or wet? This is mostly a matter of preference. Sometimes when remains are totally dry, it makes brush cleaning more difficult because dirt and fur will be cemented to the bones. However, pulling apart the dry fur and picking out the bones can be a little easier and less gross. But I have learned soaking a critter in water for a night prior to the cleaning can make the process much faster because it softens up the dirt and hair. However, soaking the body creates a mushy combination of dirt and fur, and can make some bones more fragile, like the thin vertebra processes (the spiky parts of the vertebrae), and more susceptible to breaking. It depends on what you can handle. Personally I think the benefits of soaking the critter outweigh the gross-factor of it, and I am just extra careful when working with the more fragile bones.

Whether you soak your critter or not, the first step is to dig through the fur for the bones.

^{This is my typical summer set up. Water from the hose, citronella candle for the mosquitos, my trusty strainer basket, a nice big bowl of water, and a toothbrush. I also have my containers nearby to put my bones into.}

I like to take out all the largest bones first, before starting on the vertebrae, metacarpals and metatarsals (wrist and foot bones), and finally all the tiny carpals, tarsals, and phalanges (wrists, ankles, and toes), including the tiny claws. The claws will sometimes still have the sheath over them, but these usually decay if you try to clean them, so I usually just keep the hard inner claws. I put all the bones in the strainer basket and give them a quick wash to rinse all the dirt and fur off that will give, and then start on a more intensive cleaning with my brushes.

^{I will usually set my bones on a paper towel so they don't get lost.}

With a cup of water nearby, I dip my toothbrush in and scrub at each bone where there is visible dirt. You will learn that bones can be pretty colorful, and the initial brush cleaning will not make them sparkly white. They will be greyish, brownish, and have a yellow tint inside from fat. You are only trying to get dirt and fur off the bones. The color-changing processes will come later.

If I want to keep the bones organized in the order they lay in the body, such as the vertebrae, I will put them each in their own cup. But for bones that are easily identifiable, I put them all together into one container.

A straw cleaner is a super handy too for cleaning out the holes in vertebrae.

Degreasing

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The first thing I do after cleaning my bones is degrease them. In this step, you put your bones in a container with a lid and fill it with water and dish soap. The dish soap helps draw out the lipids, or fats, in the bones. This keeps them from becoming greasy and breaking down, as the fats will continue to decompose the bone slowly over time, making them brittle, weak, and spotted with holes.

I used to think this step was optional, but after having many of my skeletons get greasy and gross over time, I now do it with all my critters. This step is super simple though, and really just involves waiting and checking.

^{Hazelnut and Hemlock squirrels after brush cleaning.}

I use about a tablespoon of dish soap for a small container.

^{Fill up the rest of the way with water.}

Make sure to cover your bones fully with liquid. Seal your lid on and give them a gentle shake side to side to get the dish soap dispersed in the water.

^{I make sure to label my containers so I know who is in them and what step they are on. Both of them are doing another round of degreasing.}

For both degreasing and whitening, I let my bones soak for about a weak before checking them. It's good to have clear containers for this step so you can check the color. If the bones are especially fatty, the liquid will become cloudy and yellowish. If it's very cloudy, make sure to open the containers outside, because you might unleash an unholy stink inside your house.

^{These are my squirrel Michel's bones, which were getting greasy so I decided to do another round of dish soap. It didn't get too cloudy after a week, so they should be good.}

You can leave your bones in there for a while, but I wouldn't leave them for much longer than two weeks. Check them occassionally to see if the water is cloudy and needs changing.

Here is Hemlock after a week of degreasing. The liquid is pretty murky, and will likely need another round. I pour all the bones in my strainer and spray them down with water until the suds are gone. Sometimes it can get pretty soapy, so just keep rinsing until it comes out clean.

Whitening

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The last step of the cleaning process is whitening! Degreasing tends to darken bones after drawing the fats out, so to regain that natural bone color, we use hydrogen peroxide to whiten them. Sometimes it's hard to tell if you need to do another round of degreasing, but whitening will reveal any greasy, yellow patches of fat left in the bones.

^{My squirrels Hemlock and Hazelnut after rinsing off the dish soap. Note the dark patches on the bones.}

Both of these squirrels came out fairly dark after degreasing. They probably need another round, but I am going to alternate whitening and degreasing to be able to tell easier.

Take your hydrogen peroxide and fill up your containers halfway, then fill the rest of the way with water. You can experiment with different amounts of water to peroxide, but I personally use half and half because I tend to leave my bones to soak for a long time and I don't want them to get too white. I aim for a more natural off-white color.

Both of these containers ended up getting very foamy, which indicates that there is still bacteria on the bones. This can be for a few reasons, but most likely it means the bones will need another round of degreasing after this round of whitening.

Note: Sometimes when your liquid foams up like this, it's good to leave it to settle for an hour before putting you lid on. The build up of gasses inside can cause your lids to pop off and make a mess.

Once your bones are much cleaner and degreased, they shouldn't foam up at all. Here is Michel's bones on his last round of whitening:

With your bones soaking in hydrogen peroxide, all you have to do is wait! You can check on them every few days to guage their progress. The longer you leave them in, the whiter they will get, so if you want a natural off-white color, make sure to check them after a week. A bright white color may take several weeks.

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Storage