The octopus dwells on the ocean bottom, where it crawls about on its long, flexible tentacles. It searches in every crevice for its favorite foods—crabs, lobsters, and shellfish.
An octopus’s tentacles are lined with cup-like suckers that enable it to grab and hold tightly to anything it catches. The octopus then tears apart its prey with its strong parrot-like beak.
Some octopuses can inject a poison with their bite. This poison is useful to the octopus in getting its food. For instance, it can render a crab helpless, and thus easy for the octopus to capture and eat. –Dick Rogers