Bees paint poo on their homes to repel giant hornets

Insects don’t come much cuter than the humble bee. Those eye-catching stripes, the waggle dance they do to tell each other where they got name-names, that thing where they sprinkle buffalo poop on their hives.

Excuse me, the most scientific term is right. But no matter what you call it, the fact remains that the Asian bee species Apis cerana flies around bird poo and water buffalo not with its hind legs, as it does with pollen, but with its mouth. Back at the colony, he applies the excrement in the form of “spots” around the entrance to the hive. It might seem like a bad mix, but scientists have just shown that there is a brilliant method to this scatological madness: Heavily spotted colonies repel the bee’s nemesis, the giant hornet. Vespa soror, a close cousin of the infamous Vespa mandarin or Asian giant hornet (colloquially nicknamed the “hornet murder”) Who invaded the United States.

If you knew what Vespa soror was capable of, you might not be so quick to judge these bees. At nearly an inch and a half long, the hornet wields massive mandibles that quickly guillotine Asian honey bees, which are about a quarter of its size. When one of them finds a nest, he slices all the workers who mount a defense and releases pheromones that mark the colony for his compatriots to find them. Soon, reinforcements burst in, the formidable air force gnawing at the small opening of the nest to get their oversized bodies through.

Once they are there, it’s like a human army breaking through the walls of a castle: things will quickly deteriorate. Hornets catch bee larvae and take them to their own nest to feed their young. “They’re hunters, so it’s like a boon to them,” says Wellesley College biologist Heather Mattila, lead author of a new paper in PLOS ONE describing insect warfare. The bees that survive eventually retreat, knowing that they are now powerless to stop the looting. “Poor Asian honey bees, they’re just plagued by a series of really relentless hornets,” Mattila says.

Join Vespa soror in the torture of these bees is Vespa velutina. Instead of infiltrating the nest, this little hornet hovers just around the colportant colony, picking up victims on the wing. Bees, however, are not entirely defenseless. They will whistle on the hornets. Most famous, they perform “heat ballIn which the tiny bees form a swarming mass of bodies around a hornet, raising their temperature until the invader literally cooks to death.