Fruit Flies

Fruit flies feed on decaying matter, most commonly fruit and vegetables. They are small flying pests that are commonly found in homes, restaurants, pubs, bars, hotels, and other facilities where food is processed. Fruit Flies are found on moist, decaying matter that has been stationary for several days.

Where Are Fruit Flies Coming From in My Kitchen?

The name “fruit fly” is misleading. While adult fruit flies are attracted to ripe and overripe fruit, the primary breeding source in most Irish kitchens is not fruit — it is the organic biofilm lining drain pipes and waste traps. Fruit fly larvae need moisture and fermenting organic matter to develop, and the inside of a kitchen drain pipe provides exactly these conditions year-round.

This is why removing fruit from the kitchen often has limited effect on a persistent infestation. The breeding is happening underground in the drain, not on the worktop. Common drain breeding sites include:

• Kitchen sink drain traps and overflow channels
• Bar and coffee machine drainage channels (particularly common in pubs and cafés)
• Dishwasher drain hoses where organic residue accumulates
• Floor drains in food preparation areas
• Recycling bins and glass collection areas in bars and restaurants

To confirm whether your drains are the source, cover the drain with clear plastic film overnight. If fruit flies are found under the film in the morning, the drain is the breeding site. Clean drain traps thoroughly with a drain cleaner that breaks down organic biofilm — standard bleach does not reach or kill biofilm effectively. For persistent or large infestations in food businesses, contact Owl Pest Control for a professional drain treatment.