How to eliminate small flies from drains?

How to eliminate small flies from drains?

Small flies from drains (drain flies) are a common problem in many households. Elimination requires systematic treatment of all drain openings, missing one may undo all efforts.

Check all drain openings

First, identify all potential breeding drain openings in your home:

• Bathroom floor drains, most common, highest numbers.
• Washbasin drainpipes (including overflow openings, many people don't know these can also breed flies).
• Kitchen sink drainpipes.
• Mop sink or utility sink drains.
• Washing machine drain hose connections.
• Balcony floor drains and air conditioner drain pipes.

Weekly boiling water flush

• Flush all drain openings with boiling water once a week.
• For overflow openings, insert a small brush to scrub, then flush with boiling water.
• Boiling water kills larvae and eggs.
• If you can disassemble the trap (U-bend) for cleaning, the effect is even better.

Apply insecticide

• Spray dinotefuran-containing household insecticide on the outer walls of all drain openings and surrounding areas.
• Also spray bathroom walls, corners, and under the sink.
• Adults that land on the treated surface die.
• Prevents newly emerged adults from flying out.

Persist for one month

The drain fly life cycle is about 2-3 weeks; larvae take time to mature and emerge. Treat weekly for one month to basically eliminate the flies. Thereafter, maintain with weekly boiling water flushes.