Beekeeper Annelies searched for nests of the yellow-legged hornet in the Dutch province of Utrecht using a vacuum cleaner and a tracking app. The species was reported to be appearing in more places in the province, while debate emerged at the end of the campaign season over whether efforts to combat the invasive insect still made sense. The hornets were described as flying over terraces, hunting bees and building nests as large as a skipping ball.