A firefighter rests next to fire combat truck during a wildfire at Penela, Coimbra, central Portugal, on June 18, 2017. A wildfire in central Portugal killed at least 25 people and injured 16 others, most of them burning to death in their cars, the government said on June 18, 2017. Several hundred firefighters and 160 vehicles were dispatched late on June 17 to tackle the blaze, which broke out in the afternoon in the municipality of Pedrogao Grande before spreading fast across several fronts. (Photo by Patricia De Melo Moreira/AFP Photo)

A demonstrator catches fire after the gas tank of a police motorbike exploded during clashes in a protest against Venezuelan President Nicolas Maduro, in Caracas on May 3, 2017. Venezuela' s angry opposition rallied Wednesday vowing huge street protests against President Nicolas Maduro' s plan to rewrite the constitution and accusing him of dodging elections to cling to power despite deadly unrest. (Photo by Juan Barreto/AFP Photo)

Sunday night, Lauren Watts searches for her dog in Mayflower, Arkansas., after a tornado struck the town. (Photo by Benjamin Krain/The Arkansas Democrat-Gazette)

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.

An interior of a car damaged by the floods is pictured in the town of Braunsbach, Germany, May 30, 2016. The flood tore through Braunsbach, crushing cars, ripping corners of houses and flooding homes during a storm that hit southwestern Germany. Miraculously no one in Braunsbach was killed, though three people died as a result of the storm in other parts of the country. (Photo by Kai Pfaffenbach/Reuters)

A man checks his mobile phone near overturned shipping containers after explosions hit the Binhai new district, Tianjin, August 13, 2015. A huge explosion hit an industrial area in the northeastern Chinese city of Tianjin late on Wednesday evening, triggering a blast wave felt several kilometres away and injuring at least 50 people, domestic media reported. (Photo by Reuters/Stringer)

A monarch butterfly rests on a visitor's hand at the Monarch Grove Sanctuary in Pacific Grove, California December 30, 2014. Monarch butterflies may warrant U.S. Endangered Species Act protection because of farm-related habitat loss blamed for sharp declines in cross-country migrations of the orange-and-black insects, the U.S. Fish and Wildlife Service said. (Photo by Michael Fiala/Reuters)

A truck remains mired in mud and debris on State Route 58 near Tehachapi, California, about 60 miles (97 km) outside of Los Angeles October 17, 2015. A mudslide on Thursday left nearly 200 vehicles, including 75 semi-trailer trucks, stuck in up to five feet of mud, local sheriff's spokesman Ray Pruitt said. (Photo by David McNew/Reuters)