The name for a group of penguins varies based on whether the penguins being described are on land or at sea. "Rookery," "waddle" or "colony" are all three terms that are used in reference to a group of penguins on land, while a group of penguins floating at sea is referred to as a "raft."
A small group of penguin chicks is called a "crèche." Penguin chicks form crèches to help them stay warm until they develop their plumage.
Penguins are unique in that the male watches the nest for up to 2 weeks at a time after the female lays one to two eggs inside. While the male is busy nesting, the female hunts for food. Upon her return, she nests while the male takes his turn hunting.