Some honeybees use animal dung to ward off giant hornets

A study from the University of Guelph is the first to discover that some honeybees use animal dung to fend off giant hornet attacks. Researchers found that honeybees in Vietnam collect and apply spots of animal dung around hive entrances to deter raids by the Asian hornet. The Asian hornet is the cousin of the so-called "murder Hornets" seen in parts of North America.Researchers also point out that the finding is the first to document the use of tools by honeybees. Giant Hornets are the biggest wasps that threaten honeybees and one of the honeybees most significant predators. The giant hornet and murder hornet are the only two species of hornets that recruit nestmates for organized attacks that can lead to nest branches.

The goal of the hornet raids is to kill the bees and carry away larvae and pupae to feed their own young. The pre-emptive defense of the honeybee is to collect animal dung and apply it to hive entrances. During the investigation, researchers discovered from beekeepers in Vietnam that the dark spots around the entrances of Asian honeybee hives was buffalo dung.

In the research, the team gathered dung from water buffalo, chickens, pigs, and cows and placed it in mounds near an apiary. By the end of the day, 150 bees visited the piles tending to collect the stinkier manure of pigs and chickens. Individual bees were marked to identify them at their hives, and videos were recorded of the marked bees applying the material at the entrance to their nest.

According to the researchers, the Hornets spend less than half as much time at nest entrances with moderate to heavy dung spotting as they did at hives with few spots of dung. The Hornets also spent only one 10th as much time chewing at the hive entrances to get inside when they were smeared with dung. It's a mystery why the dung repels the hornets, but scientists believe it might be the smell, or dung possibly helps mask odors emitted by the bees.