Honey bees use excrement to repel hornet invaders

WASHINGTON (AFP) – It’s certainly one way to defend your home.

Scientists have observed that Asian honey bees collect chicken faeces, buffalo dung and even human urine, then smear it around the entrances of their nests to stop attacks from marauding giant hornets.

The pungent practice is the first documented case of honey bees collecting non-plant matter, and the first clear example that they can use a “tool” (in this case, excrement).

A team led by Heather Mattila at Wellesley College published a study on the phenomenon in the journal PLOS ONE on Wednesday.

“We’re adding another, rather complicated defense that Asian honey bees have to an already impressive list of defenses they have to prevent these hornets from destroying their colonies,” she told AFP.

It was previously known that honey bees, famous for their prolific collection of resources, have devised an array of strategies to deflect attacks from predators.

These include physically shielding their colonies, performing synchronised body shakes or wave-like displays, hissing, or enveloping intruders in a ball until they overheat.

Giant hornets, who are four to five times bigger than honey bees, are well-armoured killing machines with a venomous sting and powerful mandibles for crushing, dismembering and chewing prey.

A scout hornet can find a honey bee nest, chemically mark it, and then recruit up to 50 of its own nestmates for a wholesale slaughter – killing thousands of their targets then occupying their home.

In the new study, Mattila and her colleagues observed three apiaries in Vietnam, where one beekeeper had informed them that the strange spots seen on honey bee nests in fact came water buffalo dung.

“We thought that’d be crazy because bees don’t collect dung,” said Mattila.

The team confirmed that the honey bees were indeed collecting dung and other excrement, which they applied around their nest entrances in response to visits by giant hornets, but not in response to visits from smaller, less threatening hornet species.

They also found that colonies that were exposed to secretions from glands that giant hornets use to mark nests for attack had more faecal spots around their nest entrance after six hours than colonies exposed to a control substance.