Seahorses are a type of fish in which the males actually get "pregnant." The female seahorse deposits her eggs in the male's specialized pouch, and the male carries up to 2,000 babies during its 10- to 25-day pregnancy.

Talk about back-breaking work—the male giant water bug (pictured above in California) literally totes around his brood of about 150 eggs until they hatch.

Male marmosets in South America not only carry, feed, and groom their twin babies (pictured, a baby black-tailed marmoset with its mother in a Tokyo zoo), they may even act as "midwives" during birth, grooming and licking the newborns.

For most birds, females are stuck with child care, but not so for the South America's greater rhea (above, chicks nestle into their dad's back feathers at Washington D.C.'s National Zoo).

The barking frog—named for its throaty, dog-like call—guards his brood after the female lays her eggs under rocks or logs in the U.S. Southwest.