Formicariidae is a family of smallish passerine birds of subtropical and tropical Central and South America known as formicariids. They are between 10 and 20 cm (4–8 in) in length, and are related to the antbirds, Thamnophilidae, and gnateaters, Conopophagidae. This family contains probably (see below) some 12 species in two fairly small genera.
These are forest birds that tend to feed on insects at or near the ground since many are specialist ant eaters. Most are drab in appearance with shades of (rusty) brown, black, and white being their dominant tones. Compared to other birds that specialize in following ants, this family is the most tied to the ground. The long, powerful legs (which lend the birds a distinctive upright posture) and an essentially vestigial tail aid this lifestyle.
They lay two or three eggs in a nest in a tree, both sexes incubating.
Systematics
The antthrushes in the genera Formicarius and Chamaeza are similar in appearance to small rails. Their sexes are alike in plumage, and they walk like starlings. The thrush part of the name refers only to the similarity in size (and in Chamaeza also coloration) to true thrushes, not to an evolutionary relationship.