[1] They are found in Central and South America, usually in moist tropical rain forests.

It is a very small family, consisting of a single genus with five extant and one fossil species.

These structures help them to cling smooth surfaces, and to remain, for example, inside young coiled banana, Heliconia, and prayer plant leaves, where they roost.

They can also be recognized by their reduced thumbs, which are enclosed by the wing membranes, and their funnel-shaped ears.

They have brownish to black fur, and roost in small groups, or singly.