No male parental care has been observed. These tarsiers have intestinal parasites and external parasites such as Trichomonas. The loud call is a loud piercing single note. The contented call is a soft sweet bird-like trill. Several individuals make a chirping locust-like communication.
Females have a vocalization that signals their approaching sexual receptivity.
Tarsiers share some characteristics of both the prosimians and the anthropoids, while maintaining characteristics unique to themselves. Taxonomists have classified them as intermediate between both groups and have assigned them to their own infraorder, which has just one living genus - Tarsius. Their relatives in the fossil record are found going back to the Eocene epoch, from 54 to 36 million years ago. Like many prosimians, they are nocturnal and have grooming claws and bicornuate uterus. In tarsiers, the internal structures of the nose and ears and the blood supply to the brain and to a developing fetus are more like those of monkeys than of lorises.