Learn how to clean and prepare animal skulls for display or study. WARNING: Veiwer disgreshion advised. Includes photos of raw skulls. Not for those with a weak stomache. Please do not leave comments about how "gross" this is. If you think it's gross, don't read it.
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Step 1: Aquire Your Skull
Of course you will first need to find a nice skull for this project. I highly recommend finding a predator skull; I find they are more interesting because of the sharp teeth. There are several places where you can find skulls.
1. Check your local taxidermist. Many times they will have small animal skulls in the freezer, such as coyote, beaver, fox, raccoon, bobcat ect. depending on where you live. They may charge you a few bucks for one, or they may even just give you a skull or two at no charge.
2. You can occasionally find raw skulls on eBay. This has the potential to get a little pricey and possibly a bit smelly, because the skull will have to be shipped to you. When searching for a specimen on eBay, type in "taxidermy skull" and search in "all categories".
3. Road kill. Use this as a last resort, as the skull will most likely be rotten and very possibly damaged.
Step 2: De-Fleshing Your Skull With Beetles
1. Dermestid beetles. This is the way many museums prepare skulls. Dermestids are small, black, flesh eating beetles. They are much less messy than other flesh eating bugs such as maggots, and they are fairly easy to contain because they cannot fly in temperatures below about 85 degrees. You can buy dermestid starter kits on eBay fairly cheap. This method is best if you plan to make cleaning skulls a hobby.
a. Set up your dermestids in a large Rubbermaid tub, preferably in and out-door heated shed (it is best to keep the room temp just at eighty degrees if possible). They will need a cotton or pine shaving bedding. Use ONLY cotton batting or cotton balls that are 100% natural cotton or use pine shavings. Do NOT use cedar shavings.
b. It is best to let your starter colony grow a bit before placing your skull in (keep the skull frozen so it does not rot or dry out). Feed you beetles raw hamburger and let them multiply for about two to three weeks. Check every few days to make sure they still have food, and also lightly mist their container with water every other day.
c. Once your colony has grown for several weeks, it is time to thaw out you skull. Make sure it is completely thawed before you place it in with the beetles. You may want to set your skull on a piece of card board instead of placing it directly on the bedding, as sometimes the bedding (especially cotton) will stick to your skull. The dermestids prefer to be somewhat hidden, so you can place a small cardboard box over the skull to provide cover for them as they eat.
d. Check on your skull about every 12 to 18 hours. make sure it stays slightly damp by misting it slightly now and again. Total cleaning time will vary. The larger and hungrier your colony is, the better. I have heard that a good strong colony can clean an entire buffalo skull in about 48 hours, but don't be disappointed if yours takes a few extra days. Make sure you do not place more than one skull in at a time, and make sure you remove the skull quickly after all of the flesh is gone, because the dermestids will begin to eat the bone.
e. Finally, when you remove the skull from your beetle tank, there will still be beetles on it. Place your skull into a plastic zip-lock bag and set it in the freezer. If you simply want to slow your beetles down, leave it in for about 15 minutes, then shake and brush the beetles back into your bug-tub. If you want to kill the beetles, leave the skull in the freezer for 24 + hours, then shake and brush the bugs off outside. Be aware: you may not be able to get all of the bugs off, so don't stress if there's one or two left inside. They will eventually break down & you should be able to wash then out down the road sometime.
Step 3: De-Fleshing With Boiling or Soaking
2. Boiling your skull. You should do this outside as it WILL make your house stink. Most outdoor grills these days have a stove burner, which works perfect. I have a freestanding propane burner (purchased from Wal-Mart) that work GREAT because I can move it away from the house. You will want to designate a pot specifically for cleaning skulls; you can buy a used pot at almost any local thrift store.
a. Start your water boiling. Reduce it to a low simmer and place your skull in. Cover with a lid if possible.
b. Check your skull as often as possible, about every 10-15 minutes. If you boil it for too long or at too high a temp, the bone may begin to separate along the joints. Once the flesh is soft and easily falls away from the bone, grab a pair of tongs and remove the skull from the pot. Allow it to cool slightly, but not all the way. Make sure you collect any teeth that may have fallen out from the bottom of the pot; you can glue these back in later.
c. Remove the remaining flesh by hand, either with gloves or without (I stopped using gloves because they get in the way too much). To remove what is left of the brain, use a bottle brush under running water; push the brush up into the skull cavity and basically brush & clean just as you would a bottle or tall glass. Keep rinsing, scraping & peeling until 90% of all the flesh is removed.
3. Soaking the flesh off of your skull. This takes a long time and STINKS but it has good results. Simply fill a Rubbermaid tub with water and place your skull in. It is best if the tub is placed in a warm shed, far from your house and from your neighbors house. Change the water every four to seven days as needed. The flesh will rot right off of the bone in the water. Some teeth may fall out but they can be glued in later. Time varies based on water temp and skull size, but expect this to last at least a month. Once you can see that all the flesh is gone, rinse under running water to remove small particles, and allow the skull to dry. I recently cleaned a deer skull in this fashion, and it can out with virtually no damage to the bone.
Step 4: Whitening and De-Greasing Your Skull
Now that the worst part is behind you, the rest should be easy. For this step you will need a small plastic tub or container as well as several bottles of 3% hydrogen peroxide ($0.99 per bottle at your local drug store).
1. Place your skull into the tub and pour in the bottles of hydrogen peroxide. You will want to make sure you use enough peroxide to completely cover the skull. Do NOT dilute the peroxide. 3% is very low strength but it is the cheapest and easiest to to get your hands on.
2. The peroxide will fizz like crazy. Allow the skull to soak over night, and the check to see the progress. You skull should begin to whiten nicely. Leave it in the solution until you reach you desired whiteness, but I would not leave it in for more than about 48 hours, as the peroxide will eventually begin to weaken the bone just enough so that it gets a few hairline cracks.
3. Once your skull has whitened nicely, remove it and wash it thoroughly under running water. If there are still small bits of flesh or cartilage on it, they should have turned a light yellow color by now and should come off easily during the final rinse. Allow your skull to dry for 24-48 hours.
4. If your skull develops any greasy dark stains, contact a taxidermist to purchase a professional de-greaser. I have herd that ammonia can be used, but I have never used it myself. The peroxide works as a de-greaser as well as a whitener, but some species have greasier bones than others.
*** I NEVER recommend using a bleach mix for whitening. This can seriously damage a skull. If you wish to use something stronger than drug-store peroxide, you can purchase 40% peroxide from a taxidermist supplier. Follow the instructions on the bottle.
Step 5: Finishing Your Skull
1. Glue in any teeth that fell out during the process using Krazy Glue super glue. Don't use a glue gun. The teeth may stick out funny or crooked, and hot glue does not last. It can also look tacky if it oozes out.
2. Buy plain, clear nail polish and paint it on both sides of all of the skull's teeth. This will help to prevent the teeth from splitting in the future.
3. I like to spray my skulls with a clear semi-gloss wood finish. This may take several coats. This is not necessary, but I like the added gloss. You can also glue the lower jaw onto the upper part of the skull if you wish to & pose it so the mouth is open in a snarl.