Against predatory wasps, including hornets, they display highly coordinated Mexican wave-like cascades termed ‘shimmering’. Shimmering starts at distinct spots on the nest surface and then spreads across the nest within a split second whereby hundreds of individual bees flip their abdomens upwards.
These wave-like figures are ineffective to stop larger predators such as birds or mammals from feeding directly from the Giant honeybees’ nests. Field observations suggest that shimmering is provoked especially by wasps. However, the evolutionary role of shimmering and, in particular, its significance as a defense behavior are so far only hypothesized, and the precise relationship between Giant honeybees and potential predators regarding shimmering is not understood.
Read more here: Plos.org: Social Waves in Giant Honeybees Repel Hornets