Hummingbirds: Trochilidae

Hummingbirds are active during the day. They are solitary, alone, pairing up only to breed. The birds are polygamous (puh-LIH-guh-mus), having more than one mate at the same time. After the birds mate, the male leaves. The female lays one to two eggs. The female incubates, sits on, the eggs to keep them warm. Eggs hatch in two to three weeks, and young birds leave the nest three weeks later.

Some hummingbirds are territorial and chase other birds away from their feeding area. Cold weather causes hummingbirds to enter torpor, a type of hibernation in which their heartbeat and other body functions slow down.