What month are hornets most active?

Hornets are most active in late summer, particularly in August and September, when colonies reach their peak size and workers are actively foraging for sugars and proteins, though activity spans from spring through fall. In spring, overwintered queens emerge and start new nests, colonies are small and hornets are less noticeable. By early summer, workers emerge and colony grows. By midsummer, colonies have hundreds of workers hunting caterpillars, flies, and other insects to feed larvae. In late summer, colonies can have several hundred to thousands of individuals, larvae that produced sugary secretions mature, so workers lose that sugar source and begin seeking sugars from human foods, ripe fruits, sodas, and nectar, making them more visible around patios and picnics and more likely to sting when competing for food. This is also when nests are largest and defensive behavior peaks. Activity decreases in October and November with first frosts, when workers die and only newly mated queens seek sheltered spots to overwinter. In warmer climates, activity can start earlier and extend longer. To reduce encounters during most active months, keep sweet drinks and food covered, seal trash cans, clean up overripe fruit, and have nests removed professionally in early summer before they grow large.