The Philippine Tarsier is a tiny animal, measuring about 85 to 160 millimetres (3.35 to 6.30 in) in height makes this one of the smallest primates. The small size makes it difficult to spot. The average adult is about the size of a human fist and will fit very comfortably in the human hand. Like all tarsiers, the Philippine Tarsier's eyes are fixed in its skull; they cannot turn in their sockets. Instead, a special adaptation in the neck allows its round head to be rotated 180 degrees. The large membranous ears are mobile, appearing to be almost constantly moving, allowing the tarsier to hear any movement. It has uniquely large eyes (disproportionate to its head and body), which are listed in the Guinness Book of Records as the largest eyes on any mammal. These huge eyes provide this nocturnal animal with excellent night vision. (Wikipedia)