A recent study suggests that the cold-blooded vertebrates are smarter and more sensitive than we think.  When we picture fish, it’s often in terms of our plates or aquarium tanks. But an Australian scientist wants us to consider the animals in contexts outside mercury poisoning scares and pet stores. According to a new paper published in the journal Animal Cognition, fish socialize, use tools, develop long-term memories, enjoy back rubs, and can likely feel pain.