The habitat range of various species of octopus covers almost the whole world, only in the polar regions they are not met, but still they penetrate northward than other cephalopod mollusks. Most often, octopuses are found in warm seas in shallow waters and among coral reefs at a depth of up to 150 m. Deep-sea species can penetrate to a depth of up to 5000 m. Shallow-water species usually lead a sedentary bottom life, most of the time they hide in reef shelters, between rocks, Under the stones and go out only for hunting.
But among the octopus there are also pelagic species, that is, those that constantly move in the water column far from the coast. Most pelagic species are deep-sea. The octopuses live alone and are very attached to their site. These animals are active in the dark, they sleep with their eyes open (only narrow the pupils), in the dream the octopuses turn yellow.
There is an opinion that octopuses are aggressive and dangerous for humans, but this is nothing more than prejudice. In reality, only the largest species demonstrate the threat to divers, and only during the breeding season. Otherwise, the octopus is cowardly and cautious. Even with an equal opponent, they prefer not to get involved, but from the big ones they hide in all possible ways. The methods of protection in these animals are numerous.