The Pygmy marmoset is the smallest monkey in the world. These marmosets communicate with each other by scent and sounds like those of bird calls. Within the group, they will also use facial expressions. At the zoo, a Pygmy marmoset can live for 20 years, however in the wild, the life expectancy is more like twelve years. As with all marmosets, parenting is divided between the male and female as well as other members of the group.