Rhesus monkeys are familiar brown primates with red faces and rears. They have close-cropped hair on their heads, which accentuates their very expressive faces.
Rhesus monkeys are Asian, Old World monkeys. Their natural range includes Afghanistan, Pakistan, India, Southeast Asia, and China. A few troops of introduced rhesus monkeys now live wild in Florida. These intelligent animals can adapt to many habitats, and some can even become accustomed to living in human communities. This is most common in India, where Hindus regard the animals as sacred and usually leave them undisturbed.
The rhesus monkey's typical diet includes roots, fruit, seeds, and bark, but also insects and small animals. They live in active, noisy troops that can include up to 200 animals. Though these monkeys are good climbers (and swimmers), troops spend a lot of time on the ground. Males are the dominant sex, but they do not remain with troops permanently, so female monkeys lead these communities. Because troops include multiple mature males and females, their members are sexually promiscuous. Females usually produce one young each year, which will be raised by its mother within the very social environment of the troop.
Rhesus monkeys have an important history with humans and have aided a great deal of medical and scientific research. Rhesus antigens found in their blood enabled doctors to identify the different human blood groups. These primates also preceded humans into space.