Figure 1. Aggregation of giant honeybee nests.

This film focuses on the social structure of the South Asian Giant Honeybee Apis dorsata (Figure 1), and demonstrates that the bees' ferocity reflects their potent defence capacity. With a unique set of defence strategies, this bee is adapted to cope with many predators. The film explains how thousands of individuals within a bee community can cooperate to defend themselves against predators. The whole repertoire of a colony's defence strategies is displayed, in the context of natural predation and under controlled experimental conditions. The following behavioral aspects are shown, as visualised by infrared camera (Figure 2):

• Wasps are prevented from effectively fixing their eyes on individual bees by wave patterns, which involve thousands of bees in the outermost layer of the 'bee curtain'. This process is pheromonally linked, via Nasonov scenting [1].
• When a wasp comes into contact with a nest, the worker bees form a ball around it and increase the temperature until the wasp dies.
• Larger predators cause the colony to produce massive waves, with all bees stretching their bodies upward, activating their flight muscles and acoustically mimicking feral mammals. This causes the nest to thicken and enlarge.
• Thousands of bees can counterattack birds and humans in a split second. This is illustrated using bee-eaters, which have a unique hunting strategy [2].
• Colonies that are not directly threatened can participate in the defence response of those that are.
• Only colonies able to respond rapidly are prepared for mass defence. Infrared recording demonstrates how an undisturbed colony mobilises its defence strategies. If disturbed, nest-warm bees emerge from deeper layers to the nest surface within one minute (Figure 3); these are referred to as 'soldier bees'. A single disturbing stimulus is sufficient to make these bees attack.
• Colonies can memorize previous disturbances and keep soldier bees on 'stand-by'. While the mobilisation of mass defence can be observed directly, the readiness of a colony to attack cannot be assessed without knowledge of its past history.