See text Hornets (insects in the genus Vespa) are the largest of the eusocial wasps, and are similar in appearance to yellowjackets, their close relatives.

Hornets are often considered pests because they aggressively guard their nesting sites when threatened and their stings can be more dangerous than those of bees.

[4] While taxonomically well defined, some confusion may remain about the differences between hornets and other wasps of the family Vespidae, specifically the yellowjackets, which are members of the same subfamily.

In the east, the species' distribution area stretches over the Ural Mountains to western Siberia (found in the vicinity of Khanty-Mansiysk).

The European hornet was accidentally introduced to eastern North America about the middle of the 19th century and has lived there since at about the same latitudes as in Europe.

The Asian giant hornet (V. mandarinia) lives in the Primorsky Krai, Khabarovsky Krai (southern part), and Jewish Autonomous Oblast regions of Russia, and China, Korea, Taiwan, Cambodia, Laos, Vietnam, Indochina, India, Nepal, Sri Lanka, and Thailand, but is most commonly found in the mountains of Japan, where they are commonly known as the giant sparrow bee.

The Oriental hornet (V. orientalis) occurs in semidry, subtropical areas of central Asia (Azerbaijan, Armenia, Dagestan in Russia, Iran, Afghanistan, Oman, Pakistan, Bangladesh, Turkmenistan, Uzbekistan, Tajikistan, Kyrghyzstan, southern Kazakhstan), and southern Europe (Italy, Malta, Albania, Romania, Turkey, Greece, Bulgaria, Cyprus).

Unlike honey bees, hornets do not die after stinging because their stingers are very finely barbed (only visible under high magnification) and can easily be withdrawn, so are not pulled out of their bodies when disengaging.

[11] The stings of the Asian giant hornet (V. mandarinia) are among the most venomous known,[10] and are thought to cause 30–50 human deaths annually in Japan.

[12] Asian giant hornet's venom can cause allergic reactions and multiple organ failure leading to death, though dialysis can be used to remove the toxins from the bloodstream.

[Jalaei et al 2016 3] Hornets, like many social wasps, can mobilize the entire nest to sting in defense, which is highly dangerous to humans and other animals.

In the case of the Asian giant hornet (V. mandarinia), this is also used to mobilize many workers at once when attacking colonies of their prey, honey bees and other Vespa species.

In field tests, 2-Pentanol alone triggered mild alarm and defensive behavior, but adding the other two compounds increased aggressiveness in a synergistic effect.

Then, the larva spins a silk cap over the cell's opening, and during the next two weeks, transforms into an adult, a process called metamorphosis.

This first generation of workers, invariably females, now gradually undertakes all the tasks formerly carried out by the queen (foraging, nest building, taking care of the brood, etc.)

As the colony size grows, new combs are added, and an envelope is built around the cell layers until the nest is entirely covered, with the exception of an entry hole.

Due to their size and the power of their venom, hornets can kill large insects such as honey bees, grasshoppers, locusts, and katydids without difficulty.

Vespa have a larger body size compared to their prey, a heavy exoskeleton to resist bee attacks, and strong mandibles and venomous sting.

As concerns hornet hunting strategies, it has been demonstrated that some species such as V. tropica and V. velutina, can use both visual and olfactory cues for the long-range detection of honey bee colonies.