Puffins feed their chicks primarily with small marine fish several times a day. The prey species of the Atlantic puffin include the sandeel, herring and capelin.
The puffins are distinct in their ability to hold several (sometimes over a dozen) small fish at a time, rather than regurgitating swallowed fish. This allows them to take longer foraging trips, since they can come back with more food energy for their chick than a bird that can only carry one fish at a time.
This is made possible by the unique hinging mechanism of their beak, which allows the upper and lower biting edges to meet at any of a number of angles.