What Are These Red Eye Flies

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What Are These Red Eye Flies

What Are These Red Eye Flies?

Humpback or phorid flies grow up to 4mm in length, are dark brown to black in colour, black eyes, a small heard and have an arched thorax when viewed at the side, hence where it gets its name humpback from.

The fly can lay up to 20 eggs at a time and will lay about approx 40 eggs every 12 hours, totally a whopping 500 eggs in her life cycle! The eggs are laid on or near the surface of decaying matter.

It only takes 24 hrs for the larvae to hatch and they go on to feed for the next 8-16 days and then they crawl into a dry spot to pupate.

The life cycle from egg to adult in ideal conditions can take just up to 14 days but if conditions are not favourable to may take up to 37 days to complete their cycle

These flies are often mistaken for fruit flies as they do look very much like a fruit fly but they have black eyes instead of red.

The humpback fly can be found throughout the world.

The most significant character of this fly is that they run across surfaces instead of flying when they are disturbed.

It is common to find phorid or humpback flies in any area where food is stored, prepared & served in both residential and commercial properties. A phorid infestation could become a potentially major health risk as they frequent unsanitary and filthy conditions and spread disease-causing bacteria onto food.

In the past we have heard reports of phorid larvae being discovered in patients open wounds in nursing homes and hospitals.

An interesting fact about this fly is that it is commonly used in forensics to determine time of death! This is why this fly is also known as the coffin fly because they can breed in human corpses, and live out their lives inside buried coffins.

In the open, the humpback fly is mostly associated with carrion and decaying vegetation. They have a rapid life cycle and large numbers can appear over a very short time, yet can cover vast distances rapidly as they are strong flyers, it is estimated they are able to travel 10 km within a 24 hour period!!

In a residential or commercial property the humpback fly may be found breeding in waste, recycle bins, grease traps, hospital waste, garbage containers really anywhere where moist organic matter is allowed to collect more than a few days.


The most important aspect in the pest control treatment of these flies is locating and eliminating the breeding areas. Without removing the breeding area, it is close to impossible to eliminate the infestation.

If the location of the breeding area is in the drain, a good drain cleaner should be used to destroy the build-up of sludge which will destroy the eggs and developing larvae.

If you have an issue with a small fly and are not sure what type it is, give us a call on 1800 819 189 (Sydney’s Best Pest Control and let us help you identify it!