Blow Fly and Bottle Fly
Family Calliphoridae

Characteristics
Size: Medium-sized flies from 1/4-inch to 3/8-inch in length.
Color: Shiny, metallic blue, green, or copper, depending on the species.

Behavior
Blow flies and bottle flies are important scavengers in nature as they are one of the first insects to reach a dead animal. These flies are part of the decomposition process that recycles nutrients back into the soil. The maggots of these flies may be used by forensic entomologists to place the time of death in murder cases. They also breed in garbage containers, dumpsters, and decaying vegetative matter (e.g., compost piles).

Habitat
These flies are extremely common and can be found one to a few at a time in homes or businesses during the warm summer months. They are attracted to buildings by food odors and also warm/cool air currents emitting through cracks around doors and windows or through doors propped open for ventilation purposes. The sudden appearance of dozens of blow flies or bottle flies within a building signals a potential dead rodent, bird, or other animal in the wall, ceiling, attic, or crawl space.

Tips for Control
In most cases involving blow flies and bottle flies around homes, the problem is twofold: (1) flies are being attracted to the building by trash containers or pet manure and (2) openings (e.g. doors) exist that are permitting flies to enter. To minimize problems with flies, take the following steps:

• Throw trash away in trash cans in plastic bags. Bags reduce odors associated with garbage and trash thus attracting fewer flies to the area.
• Locate trash receptacles as far from the building as possible. Those flies that are attracted to the area will therefore be away from the back door.
• Keep doors and windows closed unless they are equipped with tight-fitting screens.
• Ensure all edges of doors and windows have tight weatherstripping. Flies can squeeze through amazingly small cracks.

If the presence of these flies is due to a dead animal within the building, finding the location of the carcass and its removal is necessary, but is not easily accomplished.

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Cluster Fly
Pollenia rudis

Characteristics
Size: Medium-sized flies from 1/4-inch to 3/8-inch in length.
Color: Black.

They fold their wings flat over their abdomen when at rest.

Behavior
A number of insects have discovered that heated buildings are ideal for surviving the cold of winter. Such pests include box elder bugs, cluster flies, and ladybugs. As the weather cools in late summer and early fall, the sun warms the southern and western walls of buildings. The warmth attracts these insects to buildings where they crawl inside cracks and stay there for the winter. This would be fine, but during warm winter days, some insects "wake up" and end up on the inside of the building.

Habitat
Cluster flies are actually parasites of earthworms. The adult flies deposit their eggs in the soil and the larvae seek out and live off of earthworms.

Tips for Control
The best way to control cluster flies is by prevention as described below. If it's too late and they are already inside, it takes a professional to find and treat the right areas to minimize the numbers of pests seen inside. If your home has experienced a problem with overwintering pests, take the following steps next summer to prevent a recurrence:

• Seal as many cracks and holes on the outside of the home as possible, especially on the south and west walls where the sun heats the home during the late summer and fall.
• Be sure that all foundation and attic vents have tight-fitting screens.
• Check the soffit vents and any gable vents or turbine vents on the roof.
• Have your Terminix professional treat the outside west and south walls of the home near the eaves. This treatment should be completed in mid- to late August.

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Crane Fly
Family Tipulidae

Characteristics
Size: Large flies up to 1-inch long; very long, thin legs.
Color: Light brown.

Behavior
Crane flies do not invade buildings but are commonly seen around buildings at night where they are attracted by lights. These flies resemble giant mosquitoes but are not a concern because they do not have biting mouthparts. Occasionally, one or two crane flies will fly into an open door and be seen inside.

Habitat
The larvae of crane flies breed in wet soil and aquatic environments. Large populations may be seen near buildings in lawns or fields where considerable rainfall has accumulated for a period of time.

Tips for Control
No control is necessary for this fly. If seen indoors, the occasional crane fly can be killed or captured and released outside. To attract fewer of these insects to a building, exterior lights should be switched to yellow “bug light” bulbs or to low pressure sodium vapor bulbs.

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Face Fly
Musca autumnalis

Characteristics
Size: Medium-sized flies about 1/4-inch in length.
Color: Dark gray; four stripes are present on top of the thorax in front of the wings. Looks identical to a house fly.

Behavior
This fly is very closely related to the house fly and, in fact, an entomologist is needed to distinguish between the two species. If “house flies” are suddenly appearing inside a building during the fall, winter, or spring, then face flies are likely involved. The face flies status as a pest is similar to that of the cluster fly. These flies have discovered that heated buildings are ideal for surviving the cold of winter, and the face fly is one such species. As the weather cools in late summer and early fall, the sun warms the southern and western walls of buildings. The warmth attracts these insects to buildings where they crawl inside cracks and stay there for the winter. This would be fine, but during warm winter days, some flies “wake up” and end up on the inside of the building.

Habitat
Like house flies, face flies breed primarily in fresh animal manure and so are more common in buildings in rural areas near farms.

Tips for Control
The best way to control face flies is by prevention as described below. If it’s too late and they are already inside, it takes a professional to find and treat the right areas to minimize the numbers of pests seen inside. If your building has experienced a problem in the past with face flies (or other overwintering pest species), take the following steps next summer to prevent a recurrence:

• Seal as many cracks and holes on the outside of the building as possible, especially on the south and west walls where the sun heats the surfaces during the late summer and fall.
• Be sure that all foundation and attic vents (if present) have tight-fitting insect screens. Plug weep holes in brick veneer buildings with small pieces of screening or wire mesh. Do not permanently seal weep holes.
• Check the soffit vents and any gable vents or turbine vents on the roof.
• Have your Terminix professional treat the outside west and south walls of the building near the eaves. This treatment should be completed in mid- to late August.

If flies are already inside the building, complete elimination of interior invasions is often not possible. Treatments may be applied to cracks around window frames and into cracks in walls above false ceilings, but these may not reach all the voids and spaces in which flies might be waiting out the winter. Sealing cracks around window frames is helpful in excluding flies from crawling into the building’s interior rooms.

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Flesh Fly
Family Sarcophagidae

Characteristics
Size: Medium-sized flies from 1/4-inch to 1/2-inch in length.
Color: Dark gray with three stripes on top of the thorax in front of the wings; eyes are usually red; a checkerboard pattern is often present on top of the abdomen.

Behavior
Like blow flies and bottle flies, flesh flies are important scavengers in nature as they are one of the first insects to reach a dead animal. These flies are part of the decomposition process that recycles nutrients back into the soil. The maggots of these flies may be used by forensic entomologists to place the time of death in murder cases. They also breed in garbage containers and dumpsters.

Habitat
These flies are extremely common and can be found one to a few at a time in homes or businesses during the warm summer months. They are attracted to buildings by food odors and also warm/cool air currents emitted through cracks around doors and windows, or through doors propped open for ventilation purposes. The sudden appearance of dozens of flesh flies within a building signals a potential dead rodent, bird or other animal in the wall, ceiling, attic or crawlspace.

Tips for Control
In most cases involving flesh flies around homes, the problem is twofold: (1) flies are being attracted to the building by trash containers or pet manure and (2) openings (e.g. doors) exist that are permitting flies to enter. To minimize problems with flies, take the following steps:

• Throw trash away in trash cans in plastic bags. Bags reduce odors associated with garbage and trash thus attracting fewer flies to the area.
• Locate trash receptacles as far from the building as possible. Those flies that are attracted to the area will therefore be away from the back door.
• Keep doors and windows closed unless they are equipped with tight-fitting screens.
• Ensure all edges of doors and windows have tight weatherstripping. Flies can squeeze through amazingly small cracks.

If the presence of these flies is due to a dead animal within the building, finding the location of the carcass and its removal is necessary, but is not easily accomplished.

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Fruit Fly
Drosophila spp.

Characteristics
Size: Small flies 1/8-inch in length.
Color: Tan brown with red eyes; wings fold flat over body.

Behavior
Fruit flies are common in homes and commercial facilities where food is prepared and served. These flies are usually carried in on fruits and vegetables. The larvae feed on yeasts that develop within ripening/decaying fruits and decaying organic matter. They are also known as pomace flies or vinegar flies because they are common pests in facilities producing vinegar. Because these flies frequent unsanitary conditions, they are a potential health concern when they occur in food facilities and hospitals.

Habitat
Any freshly decaying, moist organic matter that sits undisturbed for five or more days. Usually associated with fresh fruits and vegetables stored at room temperatures. Once inside, adult flies emerging from a piece of infested fruit can find and exploit other potential breeding sites such as poorly maintained trash containers, recycling bins, food kicked underneath tables, coolers, etc., and garbage disposals. They also may be found breeding in dumpsters outside and flying to and entering the building through doorways. The breeding media must be continually moist for the larvae to develop and generally in a fairly fresh state of decay. Any crack or area where organic matter can accumulate can support these flies.

Tips for Control
The key to controlling fruit flies is finding the breeding sites and removing them by proper cleaning practices. Fruit flies, like other types of small flies, can be difficult to totally eliminate because they can breed in such small amounts of organic matter. A number of breeding sites can be found and eliminated while others may easily be overlooked. The inspection needs to focus on finding all sites where moist organic matter has accumulated and then removing that matter completely. Often, in homes, fruit flies are carried in on bananas and when the bananas are removed, the presence of flies disappears within a few days.

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Fungus Gnat
Family Sciaridae

Characteristics
Size: Small to tiny flies; range from 1 mm to 1/4-inch in length.
Color: Most species are black, some brown; have very long thin legs and wings.

Behavior
Fungus gnats are tiny flies that are simply annoying when found in buildings. Sometimes occurring in large numbers, they gravitate toward windows, attracted by sunlight, but may also fly about desks or be attracted to persons by cologne or perfumes. The tiny flies flitting about one’s personal workspace can be disconcerting, prompting calls to have the insects controlled.

Habitat
In nature, fungus gnats breed in the soil, in fungi, and any place where suitable molds might grow, e.g., a rotting log. In buildings, they are most often associated with the soil in potted plants and in atriums. When plants are over watered, molds in the soil are capable of reproducing thus providing a breeding medium for fungus gnats. On occasion, these flies have been found breeding in ceilings and walls where water leaks are present or have occurred, but have not thoroughly dried. Molds thrive in such damp areas and provide a place for fungus gnats (and certain fungus-feeding beetles) to breed.

Tips for Control
The control of fungus gnats involves discovering the breeding sites then drying them out sufficiently to stop the growth of molds and thus eliminating the breeding media used by the flies.

• The top inch or so of the soil in potted plants can be turned over several times to dry out the soil.
• Plants should then be watered less frequently and only when watering is necessary. Soil in potted plants should not be allowed to stay constantly wet.
• Areas where water leaks have occurred should be dried thoroughly using fans, or wet wood or other building materials need to be replaced.

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Housefly
Musca domestica

Characteristics
Size: Medium-sized flies about 1/4-inch in length.
Color: Dark gray; four stripes are present on top of the thorax in front of the wings.

Behavior
The housefly is the most common and ubiquitous fly on the planet, being found everywhere humans are found except possibly the coldest reaches of the Arctic and Antarctic. Because it frequents unsanitary areas, such as garbage and manure, this fly is considered a possible health risk and its presence indoors should be minimized. This species has sponging mouthparts so it cannot eat solid food. It regurgitates digestive fluids onto its food and then sponges up its digested liquid meal.

Habitat
This species breeds primarily in fresh animal manure and so is most common on and near farms. Lawns where dog manure is left for days can also become a significant breeding site for house flies. Houseflies can plague any building, but those located near farms and pastures are likely to experience more flies than other structures. Houseflies rarely breed indoors, but if they do, the site is usually a trash container that hasn’t been cleaned for a while or possibly rotting vegetables or fruit in a box in a restaurant storeroom or kitchen.

Tips for Control
In most cases involving houseflies around homes, the problem is twofold: (1) flies are being attracted to the building by trash containers or pet manure and (2) openings (e.g. doors) exist that are permitting flies to enter. To minimize problems with flies, take the following steps:

• Throw trash away in trash cans in plastic bags. Bags reduce odors associated with garbage and trash thus attracting fewer flies to the area.
• Locate trash receptacles as far from the building as possible. Those flies that are attracted to the area will therefore be away from the back door.
• Regularly pick up pet manure from the yard.
• Keep doors and windows closed unless they are equipped with tight-fitting screens.
• Ensure all edges of doors and windows have tight weatherstripping. Flies can squeeze through amazingly small cracks.

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Moth (Drain) Fly
Family Psychodidae

Characteristics
Size: Medium-sized flies up to 1/4-inch in length.
Color: Most species are black, a few may be brown; body and wings covered with hairs making fly resemble a small moth.

Behavior
Moth flies are associated most often with drains which is where the nickname, drain flies, originates. They are common inhabitants of sewage treatment facilities where they are known as sewage flies. Buildings located near sewage treatment facilities may experience regular infestations of flies flying from such facilities. The moth fly resembles a tiny moth in appearance and is a poor flier. It prefers dark areas and is commonly seen resting on walls near areas where it breeds. In commercial buildings, they are often seen in restrooms, mop closets, and boiler rooms, but they may appear in any area where water and organic matter may accumulate.

Habitat
Moth flies breed in heavily decaying organic matter that remains fairly wet. In fact, this fly can breed in standing water that contains suitable amounts of organic materials, such as drain traps or sump pumps. In commercial kitchens, they are mostly associated with drains and very wet, poorly maintained areas such as underneath dishwasher machines. In homes, restrooms, and similar areas, they are associated with drains.

Tips for Control
The key to controlling moth flies is finding the breeding sites and removing them by proper cleaning practices. A number of breeding sites can be found and eliminated while others may easily be overlooked. The inspection needs to focus on finding all sites where wet organic matter has accumulated and then removing that matter completely. Regular cleaning of drains using appropriate drain cleaners or bacterial drain cleaning products. Bleach and hot water do not sufficiently clean drains to control flies!

On occasion, drain line breaks under slabs or in crawlspaces can result in huge moth fly populations in homes, restaurants, or other commercial buildings. Drain breaks beneath a slab floor will require the expertise of a plumber to diagnose. If flies are found to be breeding under the slab, the slab will need to be broken open and the drain line repaired. If the wet, contaminated soil is not removed and replaced with fresh, dry soil, the moth fly problem will persist.

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Phorid Fly
Family Phoridae

Characteristics
Size: Small flies 1/8-inch in length.
Color: Tan brown with black eyes; small head; a severely arched (humpbacked) thorax when viewed from the side.

Behavior
Also known as the humpbacked fly, phorid flies are common in homes and commercial facilities where food is prepared and served, but they are also a key pest in mausoleums, food warehouses, and hospitals. Because these flies frequent unsanitary conditions, they are a potential health concern when they occur in food facilities and hospitals.

Habitat
Phorid flies are capable in breeding in more types of materials than any other structure-infesting flies. In nature, they are typically associated with dead animals and heavily decaying vegetation. In mausoleums, they are known as “coffin flies” because they breed inside bodies stored in the crypts and coffins. In buildings, they may found breeding in drains, trash containers, dumpsters, rotting produce, recycle bins, grease traps, garbage disposals, crawlspaces, and any site where moist organic matter can accumulate for five days or
longer. Phorid flies have also been found to breed in poorly stored meats, damaged containers of moist foods, and organic-based glues and paints.

Tips for Control
The key to controlling phorid flies is finding the breeding sites and removing them by proper cleaning practices. Phorid flies, like other types of small flies, can be difficult to
totally eliminate because they can breed in such small amounts of organic matter. A number of breeding sites can be found and eliminated while others may easily be
overlooked. The inspection needs to focus on finding all sites where moist organic matter has accumulated and then removing that matter completely.

On occasion, drain line breaks under slabs or in crawlspaces can result in huge phorid fly populations in homes, restaurants, or other buildings. Drain breaks beneath a slab
floor will require the expertise of a plumber to diagnose. If flies are found to be breeding under the slab, the slab will need to be broken open and the drain line repaired. If the wet, contaminated soil is not removed and replaced with fresh, dry soil, the phorid fly problem will persist.

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