The tarsiers are a small primate Family (14 species), located in the phylogenetic tree at the base of the apes. They are highly specialized mammals (eyes, locomotion). Carlito syrichta, the Philippine Tarsier, has very large eyes. When light falls on the pupils, they become small horizontal rods, looking like the eyes of a mantis insect. In darkness they are huge. I know tarsiers from different animal night houses in zoological gardens.