Adelie penguins are highly dependant on crustaceans, such as krill. Fish and amphipods can also be common foods in certain locations during certain seasons.

They arrive at their breeding grounds in October. Their nests consist of stones piled together. The male Adelie penguins summon the females with a low guttural noise followed by a loud cry. A female Adelie penguin typically lays two eggs which are brown or green in colour.

Adelie penguins have to defend their nests from other penguins who try to steal pebbles, stones, and other nest building materials. They do not drink water but instead, they eat snow.

They have a gland in their nose that takes the salt out of the ocean water that they swallow when catching fish and eating fish while in the water. Adelie Penguins are migratory penguins and after breeding, they do not return to their colonies until the next spring.