This, combined with their habitat preferences, enables these monkeys to survive quite well in proximity to people. The arboreal pygmy marmosets most often live in the trees at the naturally created edges of seasonally flooded forests, usually along a river. For these reasons, pygmy marmosets remain relatively common and are not considered to be in any immediate danger. These marmosets eat spiders and insects, which are particularly abundant in edge habitats, supplemented with fruits and occasionally small vertebrates such as lizards. Grasshoppers are their favorite meal and to catch one a marmoset may even venture to the ground, something they are loath to do otherwise.
Butterflies are another favorite.
When gum runs low, the group moves on to a new home range. A typical pygmy marmoset group of seven to nine individuals includes a breeding female and her mate along with her offspring from as many as four or five litters of singles or twins. One or two of the young are usually infants being carried by their mother, father, or older sibling, while others may be nearing adulthood. As young mature into adults, they are slowly pushed out of the group, mostly by their mother, and eventually find home ranges and mates with which to start a new family group. Several pairs or small groups of pygmy marmosets live at the Zoo.