Hornets are wasps that are closely related to, but not to be confused with yellow jackets. In all, there are about 20 hornet species worldwide, but the primary hornet in North America is the European hornet. Just like other social wasps, hornets create their nests from chewing wood into a papery pulp to raise their eggs to adults.

European hornet

You’ll tend to see hornet activity during warmer weather because hornet nests get abandoned in the winter. During this time, they’ll hide under tree bark or even inside human dwellings in order to protect themselves and their eggs. When spring hits, the surviving queens crate a new nest and this is when they become quite an issue for homeowners.

Their threat to homeowners is in their sting, as they use it to kill prey and defend their hives. Unlike bees, hornets can sting multiple times as they do not die after stinging. The toxicity of their sting depends on their species, but the Asian giant hornet is the most venomous. People must be very careful because as social wasps, hornets can mobilize the entire nest to sting in defense, creating a highly dangerous situation. Furthermore, it’s better to call an exterminating company to eliminate the entire hive. This is because if hornets are killed near their hive, their bodies may release a pheromone which can cause other hornets to attack.

Asian giant hornet

Sources:

http://en.wikipedia.org/wiki/Hornet

http://animals.nationalgeographic.com/animals/bugs/hornet/