A group of penguins is called a colony, a rookery or a Waddle, but these terms are for a group of penguins on land.
A group of penguins floating in the ocean is called a raft.
The small chicks concentrate in groups called creches, which often remain together for warmth in the absence of a developed plumage.
A group of penguins is very noisy and look chaotic, but they have the ability to recognize each other through sounds and vocalizations.