Honey bees do a waggle dance to direct other bees to sources of nectar but dancing bees like this one can be halted by a headbutt from another bee.

Now researchers have found that this headbutt is actually a warning signal.

A feeding station was set up in the lab to mimic a source of nectar then foraging bees were introduced to dangers at the station such as competition from rival colonies when foragers returned to the hive, they stopped bees dancing.

Scientists think the behavior warns dancers of a dangerous source of nectar.