The pollex is not opposable, but the hallux is. All digits have flattened nails except the second and third hind toes, which have claw-like nails used for grooming. The tail is naked except for a few hairs at the tip. The skulls of tarsiers are unmistakeable due to the huge, forward-directed orbits . These have expanded rims and are separated by a thin interorbital septum .
Tarsiers are species of secondary forest.
They are active at night and highly arboreal. They feed on insects and small vertebrates, which they capture by leaping on their prey and grabbing it with their hands. Tarsiers are usually found in family groups or by themselves. Family groups are based on a stable pair bond. They are not sexually dimorphic.