Asian honey bees (Apis cerana) are looking for more than flowers. Sometimes they scour for ... dung. As studies of bee hives in Vietnam have shown, when threatened by giant hornets (Vespa soror), worker bees hastily fly away for fresh animal feces in order to then carefully smear them around the entrance to the hive. Scientists believe that excrement scares away the deadly predator from the nest. This is the first observation of honeybees using tools and the first evidence of non-plant solids harvesting.
It is known that bees are able to learn how to use tools in a laboratory environment, but such skills have not yet been observed in natural conditions. Bees collect nectar, pollen, and plant resin to build a hive, but these are not technically considered tools. The term "tool" means an external object that the animal transforms for use for any purpose. In the case of Asian bees, manure is part of a comprehensive defense system against a formidable enemy.
Giant hornets are a species common in South Asia, the main natural enemy of local honey bees. A flock of hornets can kill thousands of bees in a matter of hours and even take over an entire hive. The stings of bees are powerless against them due to the large size and strong armor of insects. Therefore, honey plants use a special alarm system: at the sight of a hornet, a worker bee warns others with the help of pheromones. And then manure is used.
Researchers in nature simulated the smell of a giant hornet next to a bee's nest. The bees immediately began to carefully enclose the entrance to the hive with feces of birds and mammals in the form of separate slides or a whole heap of manure. After the cessation of the pseudo-attacks, the bees kept their posts for several more days. It is interesting, however, that this behavior is characteristic only in relation to the species V. soror. When attacked by the less dangerous V. velutina, which rarely attacks in flocks and usually grabs individuals outside the hive, the bees do not bother with fortification work.