Philippine tarsiers are nocturnal animals that are also active at dusk and dawn (2). They spend the day sleeping in dense vegetation or occasionally in a hollow tree, and then as the sun sets, they begin their search for insect prey. Philippine tarsiers are agile acrobats of the forest, making vertical leaps from tree to tree with ease (2). Their head can rotate nearly 360°, and this, along with their enormous eyes, gives them an excellent field of vision (2). Once an insect is spotted, the Philippine tarsier will carefully adjust its position and focus, and then leap forward to seize the prey in both hands (2), their slender fingers creating a cage in which to hold flittering insects (4). During the hours the Philippine tarsier is awake, its thin ears are almost constantly being furled or crinkled (2). Generally seen in pairs of a male and female, the Philippine tarsier gives birth to a single young. Incredibly, the well-developed young weigh 25 percent of the mother's weight, a greater percentage than any other mammal (4). These large babies are well-furred, have their eyes open (2) (4), and are immediately capable of climbing and making short hops, although full leaps are not undertaken until one month of age. As the mother moves around the trees, the young will cling to her abdomen or be carried in her mouth. At 42 days of age, the young Philippine tarsier begins to capture its own insects, and shortly after this it is weaned. In captivity, a Philippine tarsier lived for just over 13 years (2).