They are olive-green, with a brightly colored patch on top of the head. They flit about rapidly, looking for insects.
Kinglets live in evergreen trees.
Their cup-shaped nests hang near the tips of branches. The nests are made of moss, grass, and feathers. The female lays from 5 to 11 creamy-white eggs that have brown spots. Many golden-crowned kinglets stay in North America during winter. Most ruby-crowned kinglets fly to the southern part of the United States or to Central America until spring.