The pygmy marmoset is the smallest South American primate. This marmoset eats gum, nectar, animal prey, exudates and nectar if it needs to. This animal moves quadrupedally and does some clinging and leaping. These monkeys live in one male, one females monogamous family groups. They are diurnal and arboreal. The males threaten each other by turning around and displaying their genitals. They chatter when they are enraged. Mating lasts about four to ten seconds.