Size: 1/4 inch long (6–7 mm); about the width 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 (running from its head to the base of its wings); abdomen has striped or checkered markings with a yellowish underside

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

Size: 1/8 inch long (3–4 mm); about the thickness of a phone charging cable

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 across the rear portion of its abdomen

Wings: One pair of membranous wings; transparent and colorless

Size: Some species are as small as 1/16 inch (1.5 mm) while others are as big as 1/5 inch long (5 mm)

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; about the same length as its abdomen; covered in long white hairs

Body: Covered entirely with a dense coat of fine hairs

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

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

Size: 1/25–1/8 inch long (1–3 mm); smaller than the thickness of a phone charging cable

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: 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)

Size: 1/16–1/8 inch long (1.5–3 mm); smaller than the thickness of a phone charging cable

Color: Most are gray or black; some species are yellow, orange, or 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 that are long and slender

Antennae: Long, thread-like antennae

Head: Small head with moderately prominent compound eyes

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

Wings: One pair of membranous wings; color ranges from clear to smoky gray