The octopus inhabits many diverse regions of the ocean, especially coral reefs. For defense against predators, they hide, flee quickly, expel ink, or use color-changing camouflage. It trails its eight arms behind it as it swims. All octopuses are venomous, but only the small blue-ringed octopuses are deadly to humans. Octopus is also eaten in many cultures. The arms and sometimes other body parts are prepared in various ways, often varying by species. Some people keep them as pets, though they often escape even from supposedly secure tanks, due to their problem-solving skills, mobility and lack of rigid structure.
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