Hornets and wasps are much more active during fall, due to their life cycle. Once the queens mate, they hibernate and prepare the next generation of colonies, while the worker hornets won't survive the winter. Once fall rolls in, hornets switch up their diets. That's what pushes them closer to people, turning patios, picnic spots, and backyard hangouts into prime sting zones. Their drive to defend their home, combined with hunger and a ticking biological clock, makes fall encounters especially risky.