Earthworms form herds and make "group decisions", scientists have discovered.
The earthworms use touch to communicate and influence each other's behaviour, according to research published in the journal Ethology.
By doing so the worms collectively decide to travel in the same direction as part of a single herd.
The striking behaviour, found in the earthworm Eisenia fetida, is the first time that any type of worm, or annelid, has been shown to form active herds.
"Our results modify the current view that earthworms are animals lacking in social behaviour," says Ms Lara Zirbes, a PhD student at the University of Liege in Gembloux in Belgium.