Squirrel monkeys inhabit the tree canopies of tropical forests in Central and South America, places of high temperatures and high humidity. There are 5 recognized species, all with short fur, black at the shoulders, yellow or orange along the back and extremities, and white on the face.
Squirrel monkeys live together in groups of up to 500 members. The groups have a number of vocal calls, including warning sounds to protect the group from threats such as falcons, snakes, and large feline predators.
Squirrel monkeys are omnivores, eating mostly fruits and insects, but also seeds, leaves, flowers, nuts, and eggs. Their tail is not used for climbing but as an aid in balancing and also as a tool.
Because of the heat and humidity of their habitats, squirrel monkeys must use several methods to stay cool. They can only sweat through the palms of their hands and the soles of their feet, which is not enough cooling for the monkeys to survive. They also seek shaded areas and use changes in posture to dissipate heat from their body. Squirrel monkeys will also use a technique known as urine washing to maximize evaporative cooling. The monkeys urinate on their hands and rub the urine over the soles of their feet. The urine then evaporates, drawing heat away and cooling their bodies.