look at this fucking helpful father

Photograph by Holger Hollemann, European Pressphoto Agency

Male marmosets in South America not only carry, feed, and groom their twin babies, but also may act as "midwives" during birth, grooming and licking the newborns.
Marmoset dads may be so involved in parenting because of the high cost of birth for the mother: While in the womb, the babies eventually make up 25% of her body weight—equal to a 120-pound woman giving birth to a 30-pound infant.