The North American squid prefers shallow water, although ma ny species inhabit deeper, offshore waters. The squids, unlike their octopus relatives, are not solitary creatures. They swim in schools and will frequently follow the schools of fish on which they feed. Their cigar-shaped bodies are well suited for swimming. Two fins help to stabilize or balance t he body when swimming, and the internal shell, called a pen, gives support to the muscular mantle.
Squids can cruise along at constant speeds or dart about in quick jerky movements.
Squids have ten arms, two of which are called tentacles. The tentacles are longer than the arms and have flattened ends like a spatula. Suckers are on the underside of all the arms and only on the flattened ends of the tentacles. The tentacles are used fo r feeding. The suckers, which may have hooks, help capture small fish and shrimp, which are quickly torn apart by the beak.