They are native to rain-forests of Brazil , Peru , Bolivia , Ecuador and Colombia . (Source: Buzzle) Finger monkeys are, as a matter of fact, pygmy marmosets. They are also known by the names "pocket monkey"and "tiny lion". This cute little primate hugs and grips on to your finger so tight that it pulls your heartstrings and you wish you could take it home with you. Finger Monkeys The finger monkey is the tiniest living primate in the world. It's so small that it can hold on to your finger. These primates belong to the family Callitrichidae, species Cebuella and genus C. pygmaea. These wonderful pictures were sent to me today, sooo precious!!