The tarsier's eyeball does not rotate. This is compensated for by the extreme flexibility of the neck, which allows the head to turn almost all the way around. This peculiarity ensures that the large eyes and large ears work in tandem when focusing in on potential prey. The ears are always moving when the animal is awake. Tarsiers can furl and unfurl their ears. Nocturnal predators usually have very large eyes and ears.
In trees tarsiers propel themselves from branch to branch with powerful thrusts of their hind legs, using the soft, disc-like pads on their fingers and toes to grip the branches. On the ground they proceed in frog-like hops, or occasionally, they walk on all fours. Their bodies are about 9 to 14 cm (3.5 to 5.5 in.) long.
Tarsiers feed on insects and lizards and also small fish and crabs. When seizing its prey, the tarsier closes its eyes tightly to protect them from injury during the victim's struggles.
While fossils of relatives have been discovered in as far-flung places as Asia, Europe and North America, modern tarsiers are restricted to a few Southeast Asian islands. The eastern tarsier, which is also known as the spectral tarsier, is found on the Southeast Asian islands of Sulawesi, Great Sangihe, Peleng and Salayar.