The Urban Pantheist

One thing I have learned time and time again as a pest control professional, is that you usually can't solve anything by throwing poison at it. This little fly (my stupid camera did a nice job for once--this fly is less than 2 mm long) lays her eggs in the bacterial slime coating the inside of a drain. The teeny maggots hatch, and feed safely within the mucusy goo. Attempts to exterminate them with bleach and other chemicals mostly deflect off the slime. The only way to interrupt the cycle is to do the hard work of scrubbing the slime out of the drain pipe with a sturdy brush. You can follow that up with maintenance treatments of a competing bacteria (several solutions are commercially available) that eat the slime-producing creatures that make the habitat for the fly. In this case, the fly is Clogmia albipunctata* usually referred to as the "filter fly," "drain fly," "bathroom fly," and so on. As pest issues go, they're pretty minor, but they have caused some fascinatingly hideous problems in rare cases: human urinary myiasis, nasal myiasis, and occupational asthma.

* You guys have been so good--what the hell does "Clogmia" mean? Is it because they live in drains, like clogs do? That can't be right. "albipunctata" means white-spotted. The family name Psychodidae uses the word "psycho" in the sense of "butterfly or moth," since these are also known as moth flies.

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.