For its distinctive way of defending its boundaries, consider Octopus tetricus, aka the gloomy octopus. If another creature gets too close, this octopus will respond by throwing things, according to a new study published recently in the journal PLOS ONE.

Native to subtropical seas off New Zealand and eastern Australia, these cephalopods recently were caught on camera throwing shells, silt, and algae at intruders who ventured too near their dens—the first time a throwing behavior has been reported among octopuses. The targets of O. tetricus—also called the common Sydney octopus—included various fish, underwater cameras, and even each other.

Though scientists aren't totally sure what motivates the behavior, it may have something to do with “the octopus equivalent of personal