kinglet, common name for members of a subfamily of five species of Old and New World warblers, similar to the thrushes and the Old World flycatchers. Kinglets are small birds (4 in./10 cm) with soft, fluffy, olive or grayish green plumage and bright crown patches. Their distribution is circumpolar in the conifer belt. The two American species, the ruby-crowned and golden-crowned kinglets, breed in Canada and winter in Mexico. Similar are the Old World goldcrest and the European firecrest. They are active, insectivorous birds, traveling in loose bands together with nuthatches, woodpeckers, creepers, and titmice. Their hanging nests are purse-shaped. In the same order as the kinglets are the gnatwrens of Central and South America and the gnatcatchers, both of the family Polioptilidae, found from the N United States to Argentina. These dainty, slender birds are colored in soft grays and have thin, pointed bills; they feed on small insects. The blue-gray gnatcatcher of the United States and Mexico is typical of the group. Kinglets are classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Passeriformes, family Sylviidae.