Mousebirds are about 11-14 in (29-36 cm) long, at least one-half of which is made up of their long tail. This structure is composed of ten feathers of variable, but graduated length, the longest being in the center of the tail. Mousebirds have short, rounded wings, short legs, and stout feet with long toes and claws. If desired, all four of the toes can be directed forward, a rather unusual trait that can be utilized, for example, when the bird is hanging from a twig as it forages. The beak is strong and somewhat hooked, and is useful for tearing the skin of tough fruits, allowing access to the edible interior.
The plumage of mousebirds is typically a subdued combination of grey or brown, with whitish and black markings. The legs are commonly red, and the head is conspicuously crested.
Mousebirds are gregarious animals, commonly roosting in tightly packed groups of as many as several dozen individuals. Mousebirds like to clamber and creep in trees as they forage, a habitat that undoubtedly contributed to the origin of their common name.
Mousebirds feed on fruits, seeds, tender plant shoots, and even leaves. Mousebirds are voracious feeders, and birds living in the vicinity of humans are sometimes regarded as local pests, because of significant damages they may cause to crops.
Mousebirds lay 2-4 eggs in a nest placed in a tree or shrub. Both parents share in the incubation of eggs, and in the care of their young. Sometimes several males help in the rearing of the same brood, and several females will occasionally lay eggs in the same nest, and share the incubation duties, sometimes brooding side-by-side.
The six species are: white-headed mousebird (Colius leucocephalus), chestnut-backed mousebird (C. castanotus), white-backed mousebird (C. colius), bluenaped mousebird (C. macrourus), bar-breasted mouse-bird (C. striatus), and red-faced mousebird (C. indicus).