The macaques (/məˈkɑːk, -ˈkæk/) constitute a genus (Macaca) of gregarious Old World monkeys of the subfamily Cercopithecinae. The 23 species of macaques inhabit ranges throughout Asia, North Africa, and (in one instance) Gibraltar. Macaques are principally frugivorous (preferring fruit), although their diet also includes seeds, leaves, flowers, and tree bark. Some species, such as the crab-eating macaque, subsist on a diet of invertebrates and occasionally small vertebrates. On average, southern pig-tailed macaques in Malaysia eat about 70 large rats each per year. All macaque social groups are matriarchal, arranged around dominant females. In some species, skin folds join the second through fifth toes, almost reaching the first metatarsal joint. The monkey's size differs depending on sex and species. Males from all species can range from 41 to 70 cm (16 to 28 inches) in head and body length, and in weight from 5.5 to 18 kg (12.13 to 39.7 lb). Females can range from a weight of 2.4 to 13 kg (5.3 to 28.7 lb). These primates live in troops that vary in size, where males dominate, however the rank order of dominance frequently shifts. Female ranking lasts longer and depends upon their genealogical position. Macaques are able to swim and spend most of their time on the ground, along with some time in trees. They have large pouches in their cheeks where they carry extra food. They are considered highly intelligent and are often used in the medical field for experimentation. Adults also are notorious for tending to be bad tempered. (Source: Wikipedia.org, CC BY-SA)