Seagull's mouth is as white as plastic, and there is an obvious black spot at the base. The length of the mouth is about a quarter of that of the head, and it reaches half the length of the head when it is fully opened. The mouth is shaped like a flat hook, with a slightly rounded front end and a sharp corner at the end. The whole mouth is very hard and durable, suitable for grasping, opening shells and pecking all kinds of food.

Seagulls' mouths can accomplish a variety of tasks, which can be their weapons and defense tools, as well as tools for foraging and breeding. Seagulls have very flexible mouths. They can catch different kinds of food, including fish, shrimp, crab, squid and so on.