Octopuses are some of the smartest animals in the ocean. They have eight long arms covered with hundreds of suckers that help them grab things and taste their food. An octopus can change its color and texture in less than one second to hide from danger or to sneak up on prey.
These incredible creatures have three hearts and blue blood! Two hearts pump blood to their gills so they can breathe underwater, while the third heart sends blood to the rest of their body. When an octopus swims, the heart that pumps blood to the body actually stops beating.
Octopuses are also famous escape artists. They can squeeze through tiny spaces because they don't have any bones in their soft bodies. The only hard part is their beak, which looks like a parrot's beak. Scientists have watched octopuses open childproof jars, solve mazes and puzzles, and even recognize different human faces.
Some octopuses have been seen using coconut shells as portable hiding places. They pick up two halves of a shell, carry them along the ocean floor, and put them together to hide inside when danger appears.