Carpet Beetle Larva
There are no uninteresting insects, only insects that are insufficiently magnified
S_ found this little larva while cleaning out a cupboard. It was in the back of the shelf, happily chowing down on a dead ant.
So far, it just looks like your typical little thing with lots of legs. Let’s zoom in a bit:
Ah, that’s better. Now we can see that it doesn’t actually have lots of legs, what it does have is a lot of bristles that stick almost straight out, or maybe angled a bit towards the head. There are also two tufts of bristles on the tail.
On the underside, we can see the actual legs, which aren’t really a lot longer than the bristles. It also has bristles on the bottom of the abdomen that give it an amusing, needs-a-shave sort of look. Note that, unlike butterfly and moth caterpillars, it does not have prolegs on the abdomen (beetle larvae do not have prolegs, only the six true legs). We can see the legs a bit better in the next picture, where it is trying to flip itself over:
At first, I thought that this was a larva of a larder beetle, like this one I posted a few months ago. But, looking at it more closely (particularly the tufts of bristles on the abdomen), I think its actually a carpet beetle, probably genus Anthrenus . I’ve been finding these Buffalo Carpet Beetles around the house, and so there is a good chance that this larva would have grown up to be one of them. Larder beetles and carpet beetles are all types of dermestid beetles, but while the larder beetle is more into stored foodstuffs, the carpet beetles are rather keen on animal proteins that are normally considered indigestible (hair, wool, feathers, skin, exoskeletons of other insects, that sort of thing).
Carpet beetles are evidently one of those species from arid or semi-arid regions that have moved into the house environment. They are adapted to a lack of water, and so can manage in spite of the dryness of the average house. Their original environment was apparently bird and mammal nests, where they ate the bits of debris that the inhabitants shed (and, in cases where the inhabitants died, ate what was left of their mummified corpses after the flies and carrion beetles were done with them. Once the dermestid beetles finish, they leave nothing behind but the polished bones of the animals’ dry, articulated skeletons). Basically, these beetles are still living in mammal nests, it’s just that these nests are now our houses instead of a hole in the ground with, say, a badger living in it.
As I mentioned in the larder beetle entry, the diet of dermestid beetles makes them real murder on things like insect collections, taxidermy, wool products, natural-fiber carpets, and museum specimens. They are also likely to be around regardless of how clean you keep your house. Even if the carpets are synthetic fibers, there are always bits of dead skin and hair, miscellaneous organic dirt, and the remains of insects that got in, couldn’t hack the indoors environment, and died. They’re in overlooked corners, under beds, in carpets, you name it. I even found one crawling across the ceiling in a very new house downstate which has only two people living in it and no pets, and is kept scrupulously clean. Seek and ye shall find, and all that. They are there, somewhere. Count on it.
 A while back, we were doing some work on the walls in the house, and found a perfect mouse skeleton. Not a trace of hair, flesh, or skin, just a complete and undamaged skeleton still posed in its original owner’s final death throes. The dermestid beetles had obviously been at it.