Flies

Flies are attracted to food, garbage, and other organic matter, making kitchens and other areas where food is prepared or consumed a prime target for infestation. In addition to being a nuisance, flies can also transmit diseases, making it essential to control their populations in and around the home.

House Fly

Musca domestica

House flies are the most common type of fly found indoors. They feed and breed on decaying organic matter, and are most often seen around kitchen garbage and spoiled food. Infestations are usually a result of poor sanitation.

While they don’t bite, house flies have been known to transport harmful bacteria and can spread diseases like cholera, dysentery, typhoid fever, and salmonellosis by contaminating food and water.

(Photo: Mississippi State University)

House Fly

Size: 1/4 inch long (6–7 mm); about the length of a pencil eraser

Color: Dull gray and black with red eyes

Shape: Small, oval-shaped body with large eyes, 6 legs, and 1 pair of wings

Legs: 6 legs; often seen rubbing the front two together for cleaning

Antennae: Tiny antennae that are barely visible to the naked eye

Head: Large, red compound eyes that cover most of its head

Body: Look for 4 dark, longitudinal bands on the thorax; abdomen has striped or checkered markings with a yellowish underside

Wings: One pair of membranous wings; slightly yellow near the body

Fruit Fly

Drosophila melanogaster

Fruit flies are attracted to ripened fruits and vegetables. They’re usually brought into the home as microscopic eggs on the surface of moist or over-ripened produce from gardens or grocery stores.

Once inside, they mature and reproduce at an astonishing rate–adults lay up to 500 eggs, which hatch and become adults after about a week.

Fruit flies are generally harmless, but they may potentially carry bacteria and contaminate food.

(Photo: John Tann)

Fruit Fly

Size: 1/10–1/6 inch long (3–4 mm); about the length of a peppercorn

Color: Tan or brownish-yellow with red eyes

Shape: Small, oval-shaped body with large eyes, 6 legs, and 1 pair of wings

Legs: 6 legs; often seen rubbing the front two together for cleaning

Antennae: Tiny antennae that are barely visible to the naked eye

Head: Large compound eyes that are most often bright red (but can sometimes be dark-colored)

Body: Look for transverse black stripes on its abdomen

Wings: One pair of membranous wings; transparent and colorless

Drain Flies / Moth Flies

Multiple species (Psychoda spp.)

Drain flies resemble tiny moths that infest bathrooms and kitchens in large numbers, usually as a result of a slow or clogged drain.

They feed on bacteria and moist, slimy, organic matter that collects around sinks, bathtubs, and floor drains.

Drain flies do not bite or spread diseases, but they can contaminate food and water and may also trigger asthma and allergies.

(Photo: Sanjay Acharya)

Drain Fly

Size: 1/10–1/5 inch long (2.5–4.5 mm); about the length of a peppercorn

Color: Light tan to dark grayish-brown with a mottled appearance

Shape: Small, hairy, moth-shaped body with furry antennae, 6 legs, and 1 pair of wings

Legs: 6 legs; brown with white rings at the tips

Antennae: Furry-looking antennae with 13 segments and covered in long white hairs; about the same length as its abdomen

Body: Covered entirely with a dense coat of fine hairs

Wings: Broad, oval-shaped wings covered in grayish-brown hairs; look for small white spots at the edges

Phorid Flies

Multiple species (Phoridae spp.)

Phorid flies are also known as “scuttle flies” because they are weak fliers and will instead try to escape danger by running and hopping erratically across surfaces.

They’re attracted to moist, decaying organic matter, which they feed and breed in. In addition to kitchens and bathrooms, they are also frequently spotted in basements, garbage containers, drain pipes, and wall voids.

(Photo: Abbott Nature Photography)

Phorid Fly

Size: Some species are as small as 1/64 inch (0.5 mm) while others are as big as 1/4 inch (6 mm)

Color: Brown, black, or yellow

Shape: Small, hump-backed body with a small head, 6 legs, and 1 pair of wings

Legs: 6 legs; back legs are noticeably longer; sometimes called as “scuttle flies” because they like to run and hop in jerky, erratic manner

Antennae: Tiny antennae that are barely visible to the naked eye

Head: Small, bristly head tucked under its thorax; large, black compound eyes

Body: Look for a strongly arched thorax that gives it a pronounced hump-back appearance when viewed from the side

Wings: One pair of membranous wings; transparent and colorless

Biting Midges / No-See-Ums

Multiple species (Culicoides spp.)

Biting midges are tiny, bloodsucking flies that inflict sharp, painful bites on exposed skin, leaving behind burning or itching sensations, reddish bumps, and sometimes welts or blisters.

Due to their tiny size, they are hard to see and can easily crawl through window screens and door screens to get inside homes. They are most active around dawn and dusk, although biting can also take place at night.

(Photo: Tasmanian Insect Field Guide)

Biting Midge

Size: 1/25–1/8 inch long (1–3 mm); about the length of a crayon tip

Color: Gray or black

Shape: Small, oval-shaped body with a tiny head, thin antennae, 6 legs, and 1 pair of wings

Legs: 6 legs

Antennae: Thin antennae with 15 segments; about half the length of its body

Head: Tiny head with large, compound eyes; long mandibles and sharp teeth for biting; females suck blood but males do not

Body: Small, oval-shaped body with a relatively large abdomen that’s tapered at the end; turns red and swollen after sucking blood

Wings: One pair of clear or grayish-colored wings with patterns of light and dark markings (difficult to see with the naked eye due to their size)

Dark-Winged Fungus Gnats

Multiple species (Sciaridae spp.)

Dark-winged fungus gnats are small, short-lived insects that resemble tiny mosquitoes.

They normally live outside in moist soil where they feed on fungi and other organic matter. Indoors, dark-winged fungus gnats are typically spotted near houseplants, infesting potting soil.

Adult fungus gnats are completely harmless but their larvae are problematic, damaging roots and stunting plant growth.

(Photo: James K. Lindsey)

Dark Winged Fungus Gnat

Size: 1/16–1/8 inch long (1–3 mm); about the length of a crayon tip

Color: Dark brown

Shape: Tiny, mosquito-like body with a long, slender abdomen, thread-like antennae, 6 long legs, and 1 pair of wings

Legs: 6 legs; long and spindly

Antennae: Long, thread-like antennae

Head: Small head with large, compound eyes

Body: Thin, delicate-looking body with a long, slender abdomen; resembles a tiny mosquito

Wings: One pair of membranous wings with a dark, smoky gray color