Caviinae Dolichotinae Hydrochoerinae Caviidae, the cavy family, is composed of rodents native to South America and includes the domestic guinea pig, wild cavies, and the largest living rodent, the capybara.

They are found across South America in open areas from moist savanna to thorn forests or scrub desert.

With the exception of the maras, which have a more rabbit-like appearance, caviids have short, heavy bodies and large heads.

Many cavies are promiscuous, forming no long-lasting social groups, although, in some species, males maintain harems of two or more females.

In contrast, maras are monogamous, and form temporary colonial crèches to care for the young of multiple mothers.