It is also the only true hornet (genus Vespa) found in North America, having been introduced to the United States and Canada from Europe as early as 1840.

[3] Unlike most other vespines, reproductive suppression involves worker policing instead of queen pheromone control, as was previously thought.

[9] The former subspecies of V. crabro (e.g.[10][11]) are now considered to be geographic color forms; while a history exists of recognizing subspecies within many of the Vespa species, the most recent taxonomic revision of the genus treats all subspecific names in the genus Vespa as synonyms, effectively relegating them to no more than informal names for regional color forms.

[2] This is significantly larger than most common wasps (such as Vespula vulgaris), but smaller than the Asian giant hornet.

[15] Only females possess a stinger, it is a modified egg laying device (ovipositor): males cannot sting.

[3] The rove beetle Velleius dilatatus is commensal with the European hornet, living much of its life in the detritus of the nest.

[16] The nest is composed of a paper-pulp mixture created by female workers chewing up dead bark, trees, or plant matter from nearby surroundings and mixing it with their saliva.

To build the actual comb, saliva is used as a cement to piece together organic and inorganic materials that are readily available to the colony.

[3] Minerals such as titanium, iron, and zirconium are commonly found in the soil and they, too, become part of the comb walls.

Analysis of the composition of nests in northern Turkey revealed oxygen, carbon, and nitrogen as the main elements, while trace amounts of silicon, calcium, iron, and potassium were found, although none of aluminium, magnesium, or sodium, providing evidence that European hornets use the surrounding soil as a resource in building their nests.

The ratio of fibrous material to actual saliva affects the nest's ability to absorb water, and thus how well its inside stays dry.

Ensuring that only the queen reproduces is thought to be likely to benefit the organization and productivity of the colony as a whole, by reducing conflicts.

Other pentenols and pentanols are contained within these venomous sacs, but their primary purpose is likely not to warn fellow hornets that danger is nearby, because these chemicals do not induce alarm behavior.

The hornet cut free a captured insect (possibly a eumenine wasp), wrapped in silk, from the spider’s web.

[23] This behavior follows the pattern of most vespines' changing their foraging techniques from hunting to scavenging, especially once the autumn season begins.

While many of these insects are considered to be garden pests, European hornets also prey on western honey bees (Apis mellifera).

[28] Some beekeepers in Europe may keep hornets and their nests in specially designed boxes hanging on trees, on the premise that the protection they provide against wax moths is worth the occasional bee they may prey upon.

A documented case requiring treatment displayed symptoms including tingling at the site of the sting, headaches, and shortness of breath.

V. crabro venom contains neurotransmitters such as dopamine, serotonin, histamine and noradrenalineneurotoxin apamin, as well as enzymes phospholipase A and hyaluronidase, and proteins melittin and bradykinin.