The skin of octopus is covered with pigment vesicles. Octopus can change color when pigment vesicles expand or contract. By changing color quickly and blending in with the surrounding environment, its instantaneous invisibility is enough to help effectively avoid the eyes of predators.
Some octopus can not only change the color of skin, but also imitate many animals by changing their body shape. Imitate octopus and live in exposed seabed sediments. There are no corals and aquatic plants around to hide. If they feel danger, they will swim like flounder. The mimetic octopus arranges all its tentacles behind it to form a plane to imitate the appearance of flounder, because the stinging flounder keeps many predators away.
Octopus's thinking:
Jim cosgrove, an expert who has been engaged in octopus research for many years, pointed out that octopus has "conceptual thinking" and can solve complex problems by itself. It is this ability that gives it the ability to walk on two feet. Jim cosgrove wrote in the French magazine le Figaro that octopus is one of the most different creatures that have ever appeared on earth.
Octopus has developed eyes, which is the only similarity between it and humans. It is very different from humans in other aspects: octopus has three hearts and two memory systems (one is the brain memory system, and the other is directly connected with the sucker). Octopus has 500 million neurons and some very sensitive chemical and tactile receptors in its brain. This unique neural structure makes it have more thinking ability than ordinary animals.
Refer to the above? People's Network-Defensive Master Count Octopus
Refer to the above? Baidu encyclopedia-octopus