Drain Flies vs Fruit Flies — What’s the Difference?

Quick Comparison: Drain Fly vs. Fruit Fly

• Drain flies are also called sewer flies, moth flies, filter flies or sink gnats.
• Drain flies prefer the biofilm of damp places like drains.
• Fruit flies prefer fermented sugars in fruit.
• Drain flies are gray, tan, or brown; fuzzy, moth-like hairy wings.
• Fruit flies are tan/ brown, often with darker abdomens, and have red eyes.

The Difference Between Drain Flies and Fruit Flies

Yes, they’re both flies, but they do look different, behave differently, and live and breed in different habitats. While both could potentially transfer microorganisms, they are more of a signal of a sanitation or decaying matter problem nearby.

Drain Fly

• Appearance —  gray, tan, or brown; fuzzy, moth-like hairy wings often in a roof-like shape.
• Habitat — prefers slimy organic film in drains, pipes, floor drains, sinks, and garbage disposals.
• Behavior — rests on nearby walls; weak, fluttering flight.
• Risks — mainly nuisance pests; a sanitation signal of decaying nearby organic material.

Fruit Fly

• Appearance — tan/ brown, often with darker abdomens, and have red eyes.
• Habitat — prefers fermenting fruit, spilled juice, soda, alcohol, and overripe produce.
• Behavior — hovers over food and beverages as attracted by fermenting sugar.
• Risks — can transfer microorganisms; signifies that nearby food is decaying.

Signs of an Infestation

A few flies do not always mean an infestation. But repeated activity in the same location is more concerning. Drain flies: gathering around drains, or emerging after rain, or resting on nearby walls; musty odor, standing water, slow drainage. Fruit flies: circling fruit, alcohol, juice, or sweet spills.

Prevention tips

Scrub drains with a stiff brush and enzyme-based cleaner. Refrigerate ripe fruit/vegetables; dispose of any decaying food in outdoor bins. Rinse food/drink containers before recycling. Wipe away sugary spills from kitchen surfaces. Fix leaking pipes/faucets.