Because of the characteristic color of the head (light spots around the eyes on a dark muzzle), the squirrel monkeys are sometimes called the “dead head”.
Among primates in squirrel monkeys, the highest specific gravity of the brain mass is to the total body weight (1/17), which is approximately twice as high as in humans.
They communicate with each other a piercing cry that is very similar to chirring. If danger approaches them, then that monkey, who first noticed the danger, starts screaming shrilly, and at this signal her whole pack hides in bushes and trees.
It is interesting that the common squirrel monkey creates the largest groups, rather than other primates. Perhaps this is due just to the small size of an ordinary squirrel monkey, and the fact that it is easier for it to protect itself and the offspring in a large group. In the group, only about six percent are males, about thirty percent of females and more than sixty percent are offspring, or cubs.
When an ordinary squirrel monkey comes into being, it weighs only eighty grams
The female wears a cub for almost five months, and to the light it appears in a period of plenty of food. Childbirth in the female lasts about eleven minutes, however, more than an hour the detachment of the placenta lasts.
In the body of squirrel monkeys, vitamin C is not produced.
Squirrel monkeys do not like to swim, but they must be kept clean.
Their voice consists of a whistle repeated several times. When something unpleasant happens to them, they start screaming and squealing.