Very Greedy Birds

Cowbirds don't make their own nests. Cowbirds sneak into other birds' nests that already have eggs, and lay eggs of their own, for the other mommy birds to tend. A cowbird will even kick one or two of the other bird's eggs out of the nest. Then, the other mommy bird will take care of the cowbird's hatchlings. The cowbird hatchling is likely to kick a couple of the other hatchlings out of the nest, so its adopted mommy can feed it more food.