A reader who had what he thought was a fruit fly problem he’d been managing with sticky traps sent us this picture of a worm he found in the bathroom. He also recently found a moth-like bug in the bathroom and infestations near the floor and ceiling grout lines.
The moth like bug and worm that he found in the bathroom point to drain flies, also known as
“Clogmia,” (named by a pun-lover, obviously.) The Clogmia are a tiny fly, measuring only about 1-2 mm and often mistaken for fruit flies or fungus moth flies. They have a hairy body with large wings for their size which leads to them being called moth flies.
As you might guess, drain flies breed in the slime that coats drains in bathrooms, kitchens, and garages. Typically we find them coming from drains in the basement or garage that are rarely used, but they can come up through drains that are used more often. Our reader did the right thing by closing the drain, but that didn’t solve the problem.
Drain fly larva have narrow, strap like plates across the upper surface of their bodies, consistent with what we can see of the photo our reader provided. However, the reader said that the worm he found was 3.16” long at the most, which seems large for the photo and for drain flies. They may be unrelated.
To be sure, the reader could put a piece of tape over the drain where he sees the flies, bugs and worms to catch them and get a better look. To reduce the number he sees, it will be necessary to throughly clean the drains, which may mean taking out the stopper coil and using an enzyme cleaner to remove anything that might catch and harbor slime. Cleaning the walls of the drain will be necessary to eliminate the habitat and get rid of the flies (and worms) he sees.
If the reader can confirm the length of the worm or provide a clearer photo of a specimen, we might be able to make a clearer identification.