The Pygmy Marmoset, the smallest marmoset and the world's smallest monkey, is some 6 inches long excluding its tail of a further 8 inches.
Its small size allows it to hide from predators. It is native to the upper Amazon Basin.
Diet is mainly tree sap and gum but also insects and birds eggs.
Most primates have hands with fingers but marmosets have claws to run up trees and tear into tree bark.
Size comparison: Pygmy Marmoset with Geoffroy's Marmoset
Eastern Pygmy Marmoset, C. p. niveiventris
They are arboreal and diurnal. Groups compromise a breeding pair and successsive offspring.
They can fit into a hand but can leap 5 metres.