Whales never clean out their ears. Year after year their earwax builds up, leaving behind something of a life history told in fatty acids, alcohols, and cholesterols. The waxy substance builds in the ear canals of many mammals, including ourselves. Human earwax, on the other hand, is not nearly as interesting. It doesn’t offer up an autobiography, and most of us remove the waxy build-up from our ears fairly regularly (about which, more later). Still, there’s a fascinating science underlying the humdrum substance.

The proper name for the stuff is cerumen, and it’s produced only by the outermost bit of the ear canal, thanks to a mix of between one and two thousand sebaceous glands (which, on your head, also help to keep hair oily) and modified sweat glands. Add some bits of hair, dead skin, and other bodily detritus and you’ve got the recipe for earwax.

Its main function has long been thought to be primarily one of lubrication (which is why early lip balms were made of the stuff) though it’s also believed to be useful for preventing insects from creeping their way into the internal recesses of your head. But some suspect that earwax also functions as an antibiotic.