How can staff and tenants get rid of and prevent drain flies? 

Drain flies (or moth flies) can be a nuisance for building landlords in the warmer spring and summer months. They become an annoyance within some structures when they breed in the liquids found in drains, dirty garbage containers and septic tanks.

Adult flies are poor fliers and are found in great numbers on walls or flying weakly in the area where they develop. Adults are more active at night and are seen hovering over the breeding site. During the day they rest on vertical surfaces indoors and in protected areas outside.

The best method of control for these pests is maintaining clear and clean drains.  This removes the harbor areas where they breed. This will usually solve the problem without the use of pesticides.

If the problem persists, and the flies are identified as moth flies, it will require and inspection of the drain by a plumber to look for broken drain pipes.

Dan McCabe is vice-president at Magical Pest Control.