A group of squid is called a shoal or squad; a group of giant squid is a school. Groups of squid are more easily viewed at sunrise and during twilight, according to New Hampshire Public Television.

Squid are similar in structure to clams and oysters; however, they carry their shells on the inside of their bodies. Unlike other mollusks, squid are unique in their ability to adapt to their environment. Of the 375 different species of squid, some are able to emit light, and others squirt ink to avoid predators. All squid have good eyesight, and it is possible that they see in color. The two longest of their 10 tentacles grab their prey, and the sharp beak on their mouth easily breaks open shells.