Vespa mandarinia, thre Japanese Giant Hornet, measures on average from 27-45mm, but the queen can reach sizes of 55mm (to reference this, I just measured my pinky and it is 65mm). They feed on bee colonies, specifically eating the pupa, which are rich in protein. One giant hornet will scout out the bee's nest and mark it with a pheremone
. This pheremone will allow the other giant hornet's to find the nest and attack together.
There was a National Geographic show called "Hornets from Hell" which filmed a giant hornet attack on a nest of European honeybees. There were 30 giant hornets and 30,000 honeybees. The attack lasted 3 hours and all the honeybees were killed. Wow.
Video of giant hornet attack
The giant hornets can annihilate the European honeybees, but cannot attack the native Japanese honeybee. When the giant hornet tries to mark the nest with pheremone, the honeybees all swarm the hornet in tandem and move their bodies to create heat. They do not bite, but simply make a big ball of heat around the hornet. They raise the temperature above 47 degrees C, which kills the hornet, but does not harm the honeybees, who have an upper temp limit of about 50 C. The nests' location dies with the hornet and the bees survive.
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