The pygmy marmoset has sharp claws which make the pygmy marmoset excellent at climbing trees and the long tail of the pygmy marmoset gives this little monkey fantastic balance when jumping between tree branches. The low weight of the pygmy marmoset allows the pygmy marmoset to reach the canopy tree tops, a place where many of the larger species of monkey cannot reach. They are also able to turn their heads 180 degrees, an adaptation which allows them to scan the environment for predators while vertically clinging to a tree.
The pygmy marmoset survive on a specialized diet of tree gum. It gnaws holes in the bark of appropriate trees and vines with its specialized dentition to elicit the production of gum. When the sap puddles up in the hole, it laps it up with its tongue. It also lies in wait for insects, especially butterflies, which are attracted to the sap holes. It supplements its diet with berries, nectar and fruit.
The pygmy marmoset has been increasingly popular as an exotic pet, but they are very hard to keep. When a baby pygmy marmoset is taken away from the family it can often die quickly due to depression. Baby pygmy marmosets also need feeding every two hours for their first two weeks in the world so they can be very time-consuming pets. Pet pygmy marmosets can take a grave dislike towards their owners and some have been known to bite their owners and throw feces at them, as a form of attack.