Anatomy: Males are brightly colored, having a green head, a white collar, and a bright yellow bill. Females are mottled brown with a brown bill. Mallards are about 20-23 inches (51-59 cm) long.

Diet: Mallard ducks have a varied diet. They eat insects, worms, frogs, snails, slugs, small shellfish, grasses, and other plants that grow near shore.

Eggs and Nests: Mallards build cup-like nests made of grass and leaves; they are lined with duck down (delicate feathers). Nests are usually on the ground in dense undergrowth. Females lay 5-14 greenish-white eggs in each clutch (a set of eggs laid at one time). The female cares for the young.