Almost all mammals have a sector of binocular vision encompassing things that are seen by both eyes at once. Input to the brain from this sector is processed to yield a three-dimensional stereoscopic image containing information about depth and distance, mainly for objects close to and in front of the animal. The binocular sector tends to be wider in nocturnal mammals (for optical reasons) and in predators that rely on vision in hunting and seizing prey. Modern primates have a larger and higher-resolution binocular sector than most other mammals. This primate peculiarity has been variously explained as having originated as an adaptation to leaping locomotion, feeding on fruits and nectar, or visually directed predation on insects.