A cuttlefish is a type of mollusk related to octopuses and squid. It has 8 arms and 2 tentacles, as well as a cuttlebone that helps it control its buoyancy. Cuttlefish have proven more useful for scientific study than octopuses due to being more reliable in experiments and living in social groups. Cuttlefish can learn and solve mazes, and have the ability to adapt their skin color and patterns for camouflage and communication. Their intelligence and adaptations are beneficial for survival and catching prey.