The nest, whence it takes its name, is placed in the most exposed situations, as on the top of a post, a bare rock, or on a cactus.

It is composed of mud and bits of straw, and has strong thick walls: in shape it precisely resembles an oven, or depressed beehive.

The opening is large and arched, and directly in front, within the nest, there is a partition, which reaches nearly to the roof, thus forming a passage or antechamber to the true nest.
Another and smaller species of Furnarius (F.cunicularius), resembles the oven-bird in the general reddish tint of its plumage, in a peculiar shrill reiterated cry, and in an odd manner of running by starts.

From its affinity, the Spaniards call it Casarita (or little housebuilder), although its nidification is quite different.

The Casarita builds its nest at the bottom of a narrow cylindrical hole, which is said to extend horizontally to nearly six feet under ground.