Cuttlefish Can Count to Five

Don't look now, but this spineless sea creature may be able to count better than your toddler. Cuttlefish need to be savvy if they want to eat. They're always on the lookout for shrimp, fish or crabs. When a cuttlefish spots a potential victim, it shoots out two specialized, sucker-bearing tentacles and nabs it. Since these hunters have to make constant judgments about which prey are worth targeting, it would make sense for them to have advanced cognitive skills—say, the ability to count. To find out whether this was true, Tsang-I Yang and Chuan-Chin Chiao, of Taiwan's National Tsing Hua University, brought some Sepia pharaonis cuttlefish into the lab for a math exam. The researchers hatched cuttlefish eggs and waited until the animals were a month old. Then they started testing the young cephalopods. In each test, a cuttlefish waited on one end of a tank, and researchers lowered a ...