Size: 1/16–1/8 inch long (1.5-3 mm); about the width of a crayon tip

Color: Reddish-brown to black

Shape: Laterally flattened, oval-shaped body with a small head and 6 legs; does not have wings

Legs: 6 spiny, spring-like legs adapted for jumping; hind legs are particularly long and well-developed

Antennae: Tiny, club-like antennae that are too small to see with the naked eye

Head: Small, sloping head with piercing-sucking mouthparts for feeding on blood; look for 2 characteristic rows of small black spines (combs) on both sides of its head resembling a mustache (genal comb) and a mane of hair (pronotal comb)

Body: Laterally compressed (appears flat when laid on its side) with overlapping body segments; covered with dark spines