What are Phorid Humpbacked Flies?

Phorid humpbacked flies are a member of the Family Phoridae, which has around 3,500 identified species worldwide. They are also known as 'coffin flies', 'sewer flies' or ‘scuttle flies’.

In homes and businesses, these flies develop and breed wherever there is moisture, any time of the year. They commonly develop in and feed on the moist organic matter that can accumulate deep in plumbing, drains and garbage disposals. Other areas include around plumbing and drains in kitchens, bathrooms and laundry rooms, under and between kitchen appliances, garbage containers, recycling receptacles, septic systems, sewers, basements, crawl spaces and in decaying flesh. Finding these flies in your home can be a sign that you have a dead animal in your home.

Phorid humpbacked flies are a sanitation issue and are often challenging to get rid of because of where they develop and breed, which is often deep with pipes and around septic systems. Dealing with these unsanitary pests can be expensive, and may require help from a plumber, contractor and pest management professional to help you find the root of the problem.

While phorid humpbacked flies can be an issue in homes, they are more often issues for food service industry and food processing and food warehousing facilities.


What do Phorid Humpbacked Flies Look Like?

Phorid Humpbacked flies are 0.6 to 6 mm long, with dark eyes. They vary in colouring, from black to dull brown to yellow. Their thorax is arched which gives them a humpbacked appearance (which they are named after).

a single phorid humpbacked fly

They are weak flyers and often scurry erratically across surfaces. They are commonly confused with fruit flies or gnats and need to be correctly identified by a pest control professional.


The Lifecycle of a Phorid Humpbacked Fly

The average lifespan of a phorid humpbacked fly is one to two months, which is dependent on their environment.

Similar to other small flies, their life cycle has 4 phases - egg, larva, pupa and adult. Female phorid humpbacked flies typically lay 20 eggs at a time and around 500 eggs in their adult lifespan in the same unsanitary places where they feed. Phorid humpbacked fly larvae can even develop in standing water. Depending on their habitat and environment, they move from egg to adult in just 2 to 3 weeks.


What do Phorid Humpbacked Flies Eat?

They feed on (and breed in) the damp organic matter deep within drains, pipes, sewage, feces, decaying fruits, vegetables and meats, fungi garbage, dead animals, other insects, and even human cadavers. All of the above provide nourishment at the various stages of their lifecycle.

Their unsanitary feeding and breeding habits spread bacteria and disease. They contaminate whatever they have infested and any counters, items, surfaces or other food and stored pantry items they come into contact with.


Do Phorid Humpbacked Flies Bite?

No, they do not bite humans and pets. They are an unsanitary nuisance pest.


Do Phorid Humpbacked Flies Cause Damage?

Phorid humpbacked flies carry bacteria and can transmit diseases.

For the food service industry and food processing, handling and storage facilities, they are a very serious health concern and are a large financial cost to address. It can be expensive locating the source of the infestation and repairing it if needed, plus there is the cost of sanitation, disposing of contaminated food and lost business if temporary closure is needed to deal with the issue.


How Does a Phorid Humpbacked Fly Infestation Happen?

These flies develop and breed wherever moisture exists, commonly deep within drains and plumbing where organic materials accumulate. Because these areas are not often thoroughly cleaned (to the point where the organic materials are broken down and cleared), and the flies can breed and mature quickly, and they are often confused with other small flies, a phorid humpbacked fly infestation can arise and catch a home or business owner by surprise.


Signs of a Phorid Humpbacked Fly Infestation

Sighting many adult flies in your home or business is a true sign of a phorid humpbacked fly infestation.


How to Get Rid of Phorid Humpbacked Flies

Phorid humpbacked flies are extremely challenging to get rid of and can be costly since they feed and breed deep within pipes and drains.

If you think that you have a phorid humpback fly infestation you need to find the source of the infestation. Common feeding and breeding areas are very similar to fruit flies, and include: 

  • Kitchens and food preparation areas
  • Bathrooms and laundry rooms
  • Drains and in and around plumbing
  • Food storage areas, specifically fruits, vegetables and pantry items
  • Under appliances or in-between counters and large appliances
  • Garbage disposals
  • Dishwashing areas
  • Broken tiles
  • Garbage, recycling and food waste areas
  • Septic systems and line
  • Janitorial or cleaning closets, especially inside mop buckets and mop heads

When trying to locate the infestation source, we suggest the following approach:

  1. First check food storage areas for decayed food and rot, especially in bagged and boxed produce and dried goods, specifically potatoes and onions, and flour. If these were sitting on the floor or close to where there is water, drainage or plumbing, they could have gotten wet and begun to decay.
  2. If no luck, next check for a dead animal in your home or business.
  3. If you still have not identified the source, check your septic lines and septic tank for cracks and leaks with the help of a plumber. Depending on where your pipes are located, you may need to cut into walls and floors. A contractor may be needed.

You cannot get rid of a phorid humpbacked fly infestation without eliminating their food and breeding sources through implementing proper, consistent sanitation practices.

a woman cleaning a sink

Regular sanitation and preventative steps are needed to help you get rid of phorid humpbacked flies, and to help you prevent them in the future:

  • Sanitize your sinks, counters and drains daily.
  • Regularly use a bacterial digesters product in your drains to help prevent accumulation of organic materials and eliminate their common breeding and feeding source.
  • Immediately clean up food and liquid spills from countertops, sinks, floors.
  • Regularly move appliances to clean up food and liquid that has fallen or dripped down along the sides.
    • If cabinets and appliances cannot be moved, use a steam cleaner to properly clean and sanitize the tight spaces between them.
  • Wash kitchen washcloths, sponges and towels often.
  • Frequently empty and sanitize indoor and outdoor garbage, recycling and compost bins.
  • Immediately repair plumbing leaks and drips.
  • Maintain your septic lines and tanks.
  • Pay attention to what you buy to avoid unintentionally buying overripe, damaged or decaying produce.
  • Regularly inspect your produce and dispose of rotten items.
  • Properly store food and pantry items, in appropriate temperatures or containers.
  • Don’t purchase excess quantities of produce, meats or pantry items unless you plan to use them quickly or have adequate storage space in the fridge and dry storage areas of your home or business.
  • Clean food containers before putting them inside the recycling bin, especially if indoors.
  • Store garbage, recycling and compost bins away from your home’s entry points.

If you have tried all the above, and your phorid humpback fly issue persist, seek the advice from a pest control professional, like Environmental Pest Control.

Call 1 (800) 263-5055

Our Professional Team is Happy to Help!