The common marmoset (Callithrix jacchus) is a very small New World monkey that lives in Brazil. Marmosets can found in many forest habitats. Common marmosets eat gum, sap, latex, and resin from trees the most out of all the members of the Callithrix family.
A common group of marmosets is made up of 15 members, but usually has nine members. Common marmosets have a complex mating system. In a group of marmosets, there will usually be one or two females that will have babies and one male to be the father. The females are usually closely related, while the male is distantly related. If the male dies, the group will break up and form new groups. When marmosets get older, they leave the group they were raised with. It is not known why.
To show fear or submission, marmosets flatten their ear-tufts close to their heads. Marmoset alarm calls tend to be brief and high-pitched. Marmosets monitor and find group members with calls called "trills".