attic fly n [See quot 1975] esp N Cent, Upper MW
Any of var flies that often overwinter inside buildings, esp the cluster fly n 1.
1951 IN Acad. Sci. Proc. for 1950 60.182, The cluster or attic fly (Pollenia rudis Fab.) was frequently reported last spring and already this fall reports are being received. As is generally known this fly is a parasite of earthworms and in seeking winter quarters, frequently enters homes. 1965 Norwalk Reflector (OH) 20 Nov 6/5, There is no such fly that has the official name “the attic fly.” There are, however, several kinds of flies that are found in the upper areas of the home during the winter months. 1968 DARE (Qu. R12) Inf OH61, Attic fly; PA176, Attic flies. 1975 DARE File Madison WI, Attic flies—some call them cluster flies—are a little bigger than house flies. . . In the fall, the flies go to dark places like attics, and when it gets too warm they come out of the attic (sometimes down the chimney) and fly to the light. At windows they sometimes cluster in balls the size of a football. 1977 Carroll Daily Times Herald (IA) 28 Sept 17/1, The more common invaders are elm leaf beetles, boxelder bugs, attic or cluster flies, hackberry gall maker and clover mite. 2000 Iola Reg. (KS) 28 Feb 3/1, In Kansas, the most common attic fly is the face fly. . . Attic flies overwinter (hibernate) as adults in homes and other buildings. 2008 in 2017 DARE File—Internet seND, We had loads of attic flies, mud daubers, basic beetles (with the red heads) that come in on the wood, spiders by the ton, teeny black beetles, and centipedes.