Female octopuses hurl mud at unwanted males.
Female octopuses hurl mud at the opposite sex
Researchers in Australia have noticed that a species known as the gloomy octopus uses its tentacles to pick up missiles. It then drops them and emits a jet of water using a siphon beneath the eye to blast the material towards its target.
The scientists were initially unsure if the octopuses were deliberately "throwing" things at each other but soon realised that females did so if they felt harassed by the opposite sex.
Professor Peter Godfrey-Smith, of the University of Sydney, said: "We were surprised to see the behaviour, and have spent a long time trying to work it out.
"The debris is not a weapon in any normal sense, and I doubt that a throw could do any real harm to another octopus, even when shells are thrown.
"But some of them appear to be targeted and do hit other octopuses."