i read an article once about an octopus that was being kept in a lab (among other aquatic things) and one of the proffessors that ran things noticed that he was missing a lot of crabs in his other tank. Well, he checked security tapes and apparently his octopus had been getting out of its tank, crawling across 3 feet of open shelf space, getting into the crab tank, eating his fill, then going all the way back to his own tank after closing the lids behind him. very intelligent creatures