Tree frogs are frogs of the families Hylidae and Rhacophoridae. There is large variation among tree frog species. Many species are not actually arboreal (do not live in trees), but terrestrial or aquatic (live on the ground or in the water). Many tree frogs are green, while terrestrial and aquatic species are duller. They mostly feed on insects and other invertebrates, but some larger species can feed on small vertebrates. The species within the genus Cyclorana are burrowing frogs, sometimes spending many years underground.