Dust rises in the summer air, swirls in the wind and settles back down. Dust covers the plants on the side of the road and grows thick on top of our shelves and under our beds. Dust rises on one continent and settles upon another. Dust is neither mineral, nor animal, but instead a miasma, a sort of falling apart of things. Dust is dust, or so it seemed, until the 1920s, when scientists began searching houses for mites. Scientists found thousands of mites where they had expected several. House dust is not dust after all. It is mostly mites and human skin. House dust is alive.
The first time I saw a picture of a dust mite was in a doctor’s office. The mite faced me. Its eight, hairy legs crabbed along through a forest of carpet fibres. On the front of its gnathosoma (mites don’t really have heads) were pinchers, chelicerae that seemed disproportionately large, pointed as though up to no good. Long hairs trailed behind it into the background of the picture. The genus of the mite in the picture was, I later learned, Dermatophagoides, the skin eater. Species of this genus, like those of several other genera of dust mites, thrive on abandoned bits of skin. Biologists often like to ask the philosophical question whether we are currently inside or outside ‘nature’. If the mites have any say, we are in. No need to wait to be reborn in your next life. You are being reborn as you read, reincarnated only to crawl away on thousands of tiny legs.
Continue reading (PDF) in Scientific American
