Phorid Flies
December 5, 2025 - Sarah Hughson
Print
EmailPhorid flies
Phorid flies (Family Phoridae), also called scuttle flies or humpback flies, are a common nuisance pest in homes. Phorid flies are very similar to fruit flies in size and appearance, but they can be a nuisance in different ways and require different management. Phorid flies do not bite people and cannot damage homes but they often fly close to your face, which can make them very frustrating to find in the home. Rarely, they can transfer bacteria to food by landing on it after landing on drains or trash cans.
Phorid flies reproduce in moist decaying organic matter (pant and animal) which means there are many options for breeding sites in and around homes. One of the most common breeding sites is in the material that builds up inside drains with normal use. They can also develop in decaying matter in compost and trashcans. In these environments they can complete their development (from egg to adulthood) in 10 days. Adults can survive for one to two months.
The best way to manage phorid flies is to eliminate their breeding sites. This can include cleaning drains, garbage disposals and taking out compost and trash frequently, so they cannot reach adulthood and reproduce. Other items to check or clean can include: old onions or potatoes, food items that may have fallen under appliances, the inner lining of trash cans or compost bins, leaky pipes, pet enclosures, potted plants, any kind of decaying plant material, even mop heads. If you are struggling to find the source of the flies, you can try placing a clear cup or bowl over sink and shower drains and wait to see if flies come out of the drain into the container. Microbial cleaners are a good option for breaking down organic matter in drains and other areas. Bleach will not kill the flies and may react with other cleaning agents in a way that is hazardous to human health.
Sometimes the source of the flies is outdoors and they come into the home through screens or as we pass through doorways. Outdoor sites that can be checked or managed include: outdoor trash cans, composters, lawn clippings, drains, septic leakage, pet waste or any other form of damp or decaying organic matter. Outdoor sticky fly traps can be used to help locate breeding sites, but they will not significantly reduce the outdoor fly population.
If fly populations are very high and a source still cannot be found, it may be worth contacting a reputable plumber to inspect pipes for cracks or build up. Plumbers may be able to pump smoke into the pipes to help identify cracks where flies may be entering or exiting.
Resources:
North Carolina State Extension. Sydney Crawley and Matt Bertone. 2021. Phorid flies.
