We constantly have flies in our home. How can we treat them without fogging our house, which one exterminator suggested? – B.B., Augusta
A: There are a number of kinds of flies that can be found in and around homes, and it is important to know the difference because some can cause problems, some are an indicator of another problem and some are innocuous. The following flies are common.
Houseflies have a gray thorax (part where head is connected and wings are attached) with four dark stripes, and a mottled abdomen (posterior portion).
These flies are considered “filth flies” and will feed on excrement, garbage, carcasses and even human secretions from wounds and mucous membranes. If you accidentally eat the larvae (maggots) in contaminated food, they can survive in your intestine.
Little houseflies resemble houseflies but they fly in circles in the middle of a room or on a porch and don’t appear to land. They can lay their eggs in any organic material, including compost piles, pet feces, dead leaves, etc. They have been known to enter the urinary tract of sleepers and cause urinary myiasis. Don’t sleep naked if you see these flies.
Blowflies are larger than houseflies and are normally shiny green, blue, bronze or black. Blowflies feed on decaying animal matter. If you have them in your house, it is an indication of a dead animal in the wall or ceiling. These flies are used by forensic entomologists to establish the time of death in humans.
Flesh flies resemble houseflies but differ in only having three stripes on a gray thorax. Some species lay their eggs in foul-smelling dead animal matter, and others will lay their eggs in open wounds on horses, cattle and other animals.
There was a case several years ago where these flies laid their eggs in the festering wound of someone in a nursing home.
One species can lay their eggs in the noses or eyes of humans, causing myiasis, which can be serious.
Moth flies are small flies with hairy wings that resemble small moths. They are usually found in the bathroom. They will breed in the gunk buildup in drains and will often be found in the tub, on shower curtains or the wall. They are poor fliers and seem to hop around.
Fungus gnats are usually associated with overwatered houseplants. You can let your plants dry out almost to the point of wilting before rewatering. Then put about an inch of aquarium gravel on the potting soil.
That will prevent female fungus gnats from laying more eggs in the potting soil, but will allow watering of the plant. You can also place a yellow sticky trap on a stick in the soil to catch the adult gnats.
Other flies are also found in and around homes, but these are the most common. You certainly don’t want any of these flies around schools, day care centers, hospitals, nursing homes, animal shelters or other areas where they can infect people or animals.
If you have a fly problem, a good electric fly trap works well, but they are expensive.
I use an apple cider vinegar trap at our place. I monitor and identify the flies around my home with a simple fly trap. I cut the top off a plastic water bottle and invert the top into the lower portion, forming a funnel.
I put about 2 inches of apple cider vinegar in the bottle with a quarter teaspoon of sugar. Almost all flies, no matter what their normal food preference, will enter the trap. I then pour them out through a sieve, let them dry and identify them.
Gallon-size milk jugs cut as described above and baited with apple cider vinegar and sugar will catch a lot of flies in a large building or yard.
Of course, if you don’t recognize your flies, you can call a pest control professional. Any professional will instantly recognize all of the flies I mentioned.