| Version | Summary | Created by | Modification | Content Size | Created at | Operation |
|---|---|---|---|---|---|---|
| 1 | Dean Liu | -- | 1253 | 2022-11-29 01:34:20 |
Drain flies, sink flies, filter flies, or sewer gnats (Psychodidae) are small true flies (Diptera) with short, hairy bodies and wings giving them a "furry" moth-like appearance, hence one of their common names, moth flies. There are more than 2,600 described species worldwide, most of them native to the humid tropics. This makes them one of the most diverse families of their order. Drain flies sometimes inhabit plumbing drains and sewage systems, where they are harmless, but cause persistent annoyance.