The Urban Pantheist

Drain Fly Psychoda alternata, Telmatoscopus albipunctatus, or similar species

cottonmanifesto found this creature in our bathroom sink. At first it was a paradox: It seemed to have two wings, like a fly, but it had long antennae and looked fuzzy, like a moth. It was a quick job to narrow the field down to "moth flies" (family Psychodidae), a group of very small flies that breed in wet, decaying organic matter.

Drain flies specifically breed in the kind of very wet, bacteria rich organic matter that accumulates in clogged gutters, rain soaked trash cans, and old household plumbing. They do not bite (though close relatives called sand flies are blood suckers), or infest food, though one imagines that they could spread disease-causing bacteria from one place to another. In at least one case in South Africa, drain flies were found to cause health problems for sewer workers, who were inhaling large quantities of them. Controls for this animal, when deemed a pest, include cleaning and unclogging drains--and at least one product is specifically designed to help cope with them. It consists of a cocktail of competing bacteria that are supposed to eat the drain fly maggots' nursery out from under them.

Moth flies are weak fliers, but are small enough to pass through window screens. Once outside they become a component of aerial plankton, adrift beyond their control, hoping to land sometime in their 2 week adult life span near another fount of bacterial slime in which to lay their eggs. I did not find it in my research, but I propose that sometimes when one finds a house centipede stranded in a sink or bathtub, that they are hunting drain flies.