Hornet head. Coloured scanning electron micrograph (SEM) of the head of a European hornet (Vespa crabro). The compound eyes are on either side of its head, with two antennae branching off to left and right from between the eyes. The biting jaws (mandibles) are at centre and two front legs below the jaws can also be seen. This hornet is the largest of the European wasps, and has a reputation for being aggressive, though it only stings if provoked. Magnification: x6.7 when printed 10 centimetres wide.