To insure the survival of baby Pygmy Marmosets, all members of the family until will take some part in helping to raise the offspring of the dominant female. This will greatly contribute to the survivability among wild pygmy marmosets which have a 67% surviral rate of the six month of their life. A staggering figure of nearly 80% mortality rate in pygmy marmosets occurs within the first two monts of their life. Infants will be carried constantly for the first two weeks of their life, but after this they are on their own. Parents will deposit two week old infants in a specific, relatively protected places and live them their for long periods of time while the adults forage in the area. This peculiar behavior is unique to Pygmy Marmosets. Common areas that the baby Pygmy Marmosets include the groups princiap feeding tree, or another large tree in the group's home range. This technique is probably practices due to the increased size of the infants, it will also decrease the cost of infant care, and will help to protect from predators such as birds.
From about the ages of two to five months, the infants will start to move on their own and are weaned by the end of the third month. Weaning begins early in Pygmy Marmosets, at the age of eight weeks, although they will not be able to find food for themselves till they are juveniles. From the age of six to twelve months Pygmy Marmosets are considered juveniles and during this phase the dominant female will likely give birth to another litter. Pygmy Marmosets will enter the sub adult age from twelve to eighteen months in which the only physical characteristics that differ from adults are their smaller body and genital sizes. During this time playing will take up a large portion of their time, they will learn valuable skills while playing.