Callithrix pygmaea, known as the pygmy marmoset, is the world's smallest monkey. Native to the Amazonian rainforests, it thrives in dense canopies. Weighing just 100 grams, it exhibits remarkable agility. Pygmy marmosets communicate using high-pitched calls and primarily feed on tree sap, insects, and fruit.

The Callithrix pygmaea, commonly known as the pygmy marmoset, is native to the western Amazon Basin in South America. This includes regions within countries such as Brazil, Peru, Ecuador, and Colombia.

Pygmy marmosets inhabit tropical rainforests, particularly thriving in river-edge forests, floodplain forests, and secondary forests. These environments are characterized by high humidity, significant rainfall, and dense vegetation that provides ample cover and food sources.

The pygmy marmoset occupies a unique ecological niche as a specialist feeder on tree sap and gum. It uses its sharp teeth to gouge holes in tree bark to access these resources. Additionally, it feeds on insects and small amounts of fruit, which supplement its diet. The species is arboreal, relying heavily on the forest canopy for movement and foraging.