Washroom wall fly or moth?

Asked June 7, 2018, 10:59 PM EDT

An expert birder and butterfly photographer suggested to me that it can't be a moth since it only has one pair of wings!
This insect is frequently seen on washroom walls of both outdoor privy's and indoor washrooms!
I just assumed it was a fly until I took these photos and heavily cropped one!
I have posted this on my Flickr.com site: James Roderick McGillawee
Will appreciate your answer at your convenience, Thanx!!!

Outside United States

1 Response

Dear Client,

This insect fools a lot of people who first see it as a moth. Nevertheless, it is a fly because it only has one pair of wings. The common name of this fly is the moth fly (Psychodidae), the drain fly or the sewer gnat. The larvae are associated with slow-moving nutrient-laden water and pumping drains, sewer systems. It is sometimes considered a nuisance pest in households. For more information on this family of flies, see:


Hope this helps!