Female octopuses off the coast of Australia have a unique way of shooing away annoying pesky males: they throw things like shells and silt at them!
Research by Peter Godfrey-Smith and others at the University of Sydney revealed that female Sydney octopuses (Octopus tetricus) hold silt, shells, and other objects under their bodies in their tentacles and then angle their siphon and shoot a jet of water to propel the objects towards another octopus, often hitting them.
In 2016, Godfrey-Smith observed a female octopus throwing silt 10 times at a male from a nearby den that was trying to mate with her. "That sequence was one of the ones that convinced me [it was intentional]," he said to New Scientist.
But not all octopus throw things at a target. Godfrey-Smith noted that sometimes the octopus throw things into empty space after intense interaction with another animal, suggesting that they were venting their frustration. In one instance, a male octopus threw a shell in a random direction after his mating attempt with a female was rejected.
Image by Peter Godfrey-Smith with illustrations by Rebecca Gelernter