Phorid Flies (Humpbacked Flies): Hidden Drain and Waste Sources

Small flies that run in quick darting bursts instead of flying away are often phorid flies.

The short answer

Phorid flies are tiny, humpbacked and run quickly across surfaces. They breed in decaying matter, damaged drains, wet waste, rotting produce and sometimes in hidden leaks. Finding the source is key: check drains, bins, under appliances, floor traps and cracked pipes. Clean and repair, then monitor. Persistent cases may need a professional or plumber.

Identification

• Small, brown to black with a humped back.
• Run in zigzags on surfaces.

Find the source

1. Check drains, traps and floor wastes.
2. Look under sinks, appliances and bins.
3. Inspect for leaks and cracked pipes.
4. Check rotting produce and spills.

Fix

• Clean thoroughly.
• Repair leaks and drains.
• Dispose of waste.

When to call a professional

If the problem is widespread, keeps returning or you are unsure what you are dealing with, a professional inspection will save time and avoid wasted effort.

Frequently asked questions

Are they harmful?

They can spread germs from waste.

Do sprays help?

Not alone.

How long do they take to clear?

Days to weeks after removing the source.

Are they fruit flies?

Different, look at behaviour.

This guide is part of IPest's complete resource on fly control. For identification help, prevention and treatment options, see our full fly control guide for Bangalore.