When you think of an animal that reacts to people, what comes to your mind? Is it a dog, a cat or a house? You probably don't think of an octopus. To most people, the octopus seems like a stupid marine animal because of its strange appearance. But octopus have very large brains, and they are intelligent. For example, an octopus is in an aquarium, and it sees food outside. What happens? It finds a way to reach the food with its long arms. Octopus are also very strong, and often they remove obstacles that separate them from their meal.