A fuzzy caterpillar on a basil plant in west Bengal, India on December 25, 2023. The caterpillar’s defence system is its hair, which has microscopic barbs that break off easily in the skin of would-be predators. (Photo by Soumyabrata Roy/NurPhoto/Rex Features/Shutterstock)

Damselflies covered in dew rest on a wild flower by the Po River, northern Italy on August 15, 2016. (Photo by Alberto Ghizzi Panizza/Barcroft Images)

Bees fly in front of a beehive in the outskirts of Frankfurt, Germany, Monday, April 8, 2024. (Photo by Michael Probst/AP Photo)

A fly rides a butterly, July 2016. (Photo by Petar Sabol Sharpeye/Rex Features/Shutterstock)

Hornets are insects that are the largest eusocial wasps. Some species can reach up to 5.5 cm (2.2 in) in length. The true hornets make up the genus Vespa and are distinguished from other vespines by the width of the vertex (part of the head behind the eyes), which is proportionally larger in Vespa and by the anteriorly rounded gasters (the section of the abdomen behind the wasp waist). The best known species is the European hornet (Vespa crabro), about 2–3.5 cm in length, widely distributed throughout Europe, Russia, North America and Northeast Asia.

“Window of Autumn” by Hasan Baglar taken in Nicosia, Cyprus, which has come first in the All About Plants Section for the RHS Photographic Competition 2019. (Photo by Hasan Baglar/RHS/PA Wire Press Association)

A Dead Leaf butterfly (Kallima inachu formosana, also called Orange Oakleaf Butterfly) rests on a tree trunk at the Taipei Zoo in Taipei, Tawian, 03 August 2019. Dead Leaf butterfly can be found in Tropical Asia from India to Japan. When its wings close, it resembles a dead leaf, providing camouflage against predators including birds, ants, spiders and wasps. (Photo by David Chang/EPA/EFE)

A grasshopper rests on a photographic camera during a meeting in the village of Alto Jamari called to face the threat of armed land grabbers invading the Uru-eu-wau-wau Indigenous Reservation near Campo Novo de Rondonia, Brazil on January 30, 2019. (Photo by Ueslei Marcelino/Reuters)