Hornets are often considered pests, as they aggressively guard their nesting sites when threatened and their stings can be more dangerous than those of bees. There are now four types of hornet in Spain with three being introduced, considered invasive and a threat to endemic wildlife. (A fifth is often mentioned in the press but the Asian giant hornet (Vespa Mandarina) is NOT present in Spain).
- Hornets (insects in the genus Vespa) are the largest in the wasp family and some species can reach up to 6 cm in length. There are around 22 species of Vespa in the world and most only occur in the tropics of Asia.
- Like other social wasps, hornets build communal nests by chewing wood to make a papery pulp. Each nest has one queen, which lays eggs and is attended by workers that, while genetically female, cannot lay fertile eggs. Male hornets are docile and do not have stings.
- Most species make exposed nests in trees and shrubs, but some build their nests underground or in other cavities.