The Rhesus Macaque, also known as a Rhesus Monkey, is one of the better-known monkeys. They are kept as pets, used in research and have even flown into space.

The Rhesus Macaque is a very social monkey. In the wild, they live in multi-male, multi-female groups, where the females are dominant. Typically, one female and one male will be dominant over the group, but the female will outrank the male. Rank is inherited. Groups usually average 20 but groups as large as 180 have been noted. Most females will remain within the groups they are born into, while males will often migrate at maturity. Males have a tendency to fight amongst themselves, while females live very harmoniously with each other. Females will participate in group grooming, which further enhances their bonds. Subgroups are often formed when existing groups grow larger. Often one group is dominant over others when competing for natural resources, such as food. Groups are rarely seen fighting with each other, rather the weaker group will submit naturally to the stronger one. The Rhesus monkey is both arboreal and terrestrial; in addition they have a great love of water and are commonly seen swimming and playing in it. Rhesus Macaques are highly active and very vocal. Two common vocalizations seen among these monkeys are scream calls used for warning and coo calls used by babies. The Rhesus Macaque is a highly intelligent monkey, which may explain why it is so commonly used in research. Education of the young takes place within groups. Young Rhesus Macaques are taught everything from parenting and social skills to what types of food are good to eat. If Rhesus Monkeys are not reared in a group, they have no knowledge of mating or raising young. These are all learned behaviors. Rhesus Monkeys are so intelligent that they have been shown to have knowledge of familial lineage, such as who is their grandmother, mother, sister, son, cousin etc. They are very communicative monkeys and use several different methods including, facial expressions (such as the fear grimace, open mouth stares and lip smacking), auditory calls and body postures (such as erect tail carriage which can display aggression or submissions). Rhesus Macaques like a wide variety of foods. In the wild, they are commonly seen to eat fruits, berries, leaves, flowers, grains, ground herbs, grass, algae and insects. They are also known to raid human areas, such as gardens, crops and garbage for food. Owning a Rhesus Macaque is not for everyone. Only those with significant primate experience should even consider them as a pet. While they are irresistibly cute as babies, they become very aggressive upon maturity. They have been known to inflict serious bite wounds on their owners. In addition, they can be quite destructive.

The Rhesus Macaque is a medium sized primate with mature males weighing six kilograms and mature females weighing approximately three kilograms. They measure anywhere from 47centimeters to 64 centimeters in length, with males being larger than females. The Rhesus Macaque has gray and brown hair covering most of his body. No hair is present on the ears, face and buttocks. The buttocks are typically a reddish color. All Rhesus Macaques have food pouches inside their mouths, which they use to store food when gathering.

The Rhesus Macaque is native to Asia. In India, they are considered sacred and they are not as endangered as they are in other areas. In fact, they live very closely with humans in India. They are so intertwined with humans in India that some consider them a pest. They are also considered pests in other areas, including Sri Lanka. In addition, because they are so used to humans and show little fear, they are considered by some to be a potential danger. In the wild, they prefer areas of open grasslands, mountain regions and dry open woodlands. The Rhesus Macaque is relatively adaptable and is very commonly seen living near humans. Their main limitation in habitat is food availability.

Rhesus Macaques are not for everyone. They generally do not make suitable pets because of their aggressive behavior and potential for destructive behavior.

They are highly intelligent social animals. If left in a cage alone without proper stimulation, they will often develop psychological problems, which lead to self-mutilation. They should be housed in very large cages with many toys and things to climb. Their captive environment should mimic their natural environment as much as possible. Because they are such social animals, keeping them singly is often not recommended.

Female Macaques are sexually mature at three years of ages, while males are not ready until they are four years old. Mating rituals between Rhesus Macaques has often been described as promiscuous. Females will often mate with several group males. When the female Rhesus Macaque undergoes estrus, her back legs and buttocks become a darker deeper red. During mating season, the males will also develop redder coloring in these areas. When a female is in estrous, she will 'present' herself to the male. Presenting is a particular behavior pattern that tells the male she is ready to mate. Once pregnant, the gestation period lasts anywhere from 135 to 194 days. They typically give birth to a single baby. Breeding in captivity seems to occur readily in settings such as zoos.