"Puffins eat small marine animals, mainly fish such as capelin and sandlance. Other fishes, as well as crustaceans, squid, and marine worms, are taken when those are less available. When feeding, a puffin swims at the surface of the sea much as a duck would, then dives head-first underwater. The bird probably swims down through the water until it reaches a depth at which its prey can be caught, pursues suitable fish or other food items, and grabs one after another with its beautifully fashioned but deadly bill before returning to the surface.

Adults hold fish crossways in their bills while carrying food back to their chicks. Chicks are normally fed about 10 g of food four to ten times per day, mostly in the morning. Adults usually carry only one or two 12 to 15 cm capelin or sandlance at a time, but more if the fish are smaller. The record number of fish held at one time by a puffin in Canada is 61. These were larval sandlance 2.3 to 3.3 cm long that together weighed only 2.3 g, about the same as a half teaspoon of water, and that unfortunately were low in energy value.

How can a puffin catch and hold 61 fish in its bill? In the puffin’s mouth a series of backward-pointing spines project from the tongue and top of mouth and hold the food in place while more is being caught." ----- From Hinterland Who's Who