The smallest monkey species in the world weighs just over 100 grams

An Eastern pygmy marmoset (Cebuella niveiventris) at the Pilpintuwasi Butterfly Farm and Amazon Animal Orphanage. (Source: Instagram/@natgeo)

These monkeys like to live in family groups that include a male, female, their children and perhaps another adult. Communication between one another takes place through vocalizations, chemical secretions, and visual displays. There are two sub species of pygmy marmosets – eastern and western, both of which have nearly identical features.

As with other marmosets, only one female breeds, and they usually give birth to twins – with each weighing around half an ounce. The whole family pitches in with childcare.

Can they make good pets?

As the top four smallest types of monkeys are all marmosets, one might imagine that their size would make them good candidates for an exotic indoor pet. However, they are not recommended as a good choice for several reasons.

For one, they like to mark territory with scent, so would be unsuitable for indoor living. They are also very social creatures and thrive within their family group, so separating one out would not be in its best interests. And lastly, while intelligent creatures, they get easily bored and can be a handful.

The Smithsonian Magazine writes that their habitats, known as gallery forests, border rivers in the Amazon basin that are seasonally flooded. However, gallery forests’ proximity to water makes them attractive to people who want to build houses with yards that slope down to the river. This development, along with agriculture and the oil industry, has slowly carved into the places where pygmy marmosets live.