You may be disturbed to learn what kinds of things live in and on you. You’d be even more disturbed if you saw little pictures of them with chapter-long descriptions, as in the book Furtive Fauna: A Field Guide to the Creatures Who Live on You. Here are just a few of the tenants of the housing project you call your body:

At least 500 species of bacteria, weighing about 3.3 pounds, live inside the human gut.

There are little arthropods called Demodex mites that live in the follicles of your eyelashes.

Without regular brushing, you likely have a film of bacteria 300 to 500 cells thick on the surface of your teeth called Streptococcus sanguis.

So maybe it’s a good thing that your mouth produces almost two pints of saliva every day.

Bone-us fact (this explains a lot):

The human head contains 22 bones.