How smart are octopuses?

Octopuses, some 300 species of which inhabit tropical waters around the world, can change colors, squirt out poison, and exert a force greater than their own body weight. But calling the eight-armed cousin of your garden snail "smart" seems a bit of a stretch. read more

Yes, but of course one has to ask what that means. read more

Correction, June 25, 2008: The original version said that early cephalopods used bursts of air to propel themselves, and that octopuses used jets of water to push toys around a tank. In both cases, the animals used water, not air. read more

The only way the male octopus could have made it into the female's tank, Caldwell said, is for the male to have wriggled through the pipe that fed water into both octopuses' tanks, an act some might deem proof of a calculated nighttime tryst. read more