Officially known as the Asian giant hornet (Vespa mandarinia), the winged menace has been sighted in the UK and the US. The hornets are known for their violent tendencies to decapitate bees, entering a so-called "slaughter phase" that has earned them their murder hornet nickname. According to the US Washington State Department of Agriculture (WSDA), the hornets are known to wipe out entire populations of honeybees by attacking hives and taking over their broods.