The European hornet (Vespa crabro), commonly known simply as the "hornet", is the largest European eusocial wasp. The queen measures 25 to 35 mm (1–1.4 in) long; males and workers are smaller. In males, as in most members of the Aculeata, the antennae have 13 segments, while in females there are only 12; also as in other aculeates, the male abdomen has seven visible segments, while the female has six; females possess an ovipositor modified into a sting which is not barbed.
This species is not particularly aggressive except when defending the nest, and care must be taken when in its proximity, as the stings are quite painful. As with most stinging insects, European hornets will sting in self-defense when grabbed or stepped on.
Eyes are deeply indented, shaped like a C. Wings are reddish-orange, the petiolate abdomen is brown striped with yellow. The European hornet is larger than common wasp. It has hair on the thorax and abdomen, although the European hornet is not as hairy as most bees.