When the grubs become adults, they take over housekeeping, nest expansion, hunting and care of the grubs. The activity of the queen during the rest of the season is limited to laying eggs. The nest will continue to grow in size as the number of hornets increases. About mid-July, production of sexually active males and females begins. Until this time, only non-reproductive females are produced.
European hornets come into conflict with man in several ways.
Basically, problems arise when the hornet tries to utilize space or resources that humans are using. This is really a competition for resources between man and insect. Nest located too close to house or other structure utilized by humans. Hornets hunting in human use area. Hornets attracted to lights.