Can a hornet harm you?

Yes, a hornet can harm you because it can sting and inject venom that causes pain, swelling, and allergic reactions, and in rare cases life threatening anaphylaxis, though most hornet stings cause only local pain and swelling that resolve within hours to days, and hornets are not aggressive unless threatened. Harm from hornet includes painful sting with sharp burning pain, redness, swelling, and itching around sting site, and multiple stings increase venom load and risk of severe reaction, as hornets can sting multiple times unlike honeybees. For people allergic to hornet venom, sting can cause severe allergic reaction with difficulty breathing, swelling of face and throat, hives, dizziness, and drop in blood pressure requiring emergency treatment with epinephrine. Hornets defend nests vigorously and will chase and sting intruders who disturb nest, releasing alarm pheromones that attract other hornets to defend, increasing harm risk if nest disturbed. However, hornets are also beneficial predators that control pest insects and pollinate, so they are not harmful in sense of seeking out humans to attack, they sting defensively. To reduce harm, keep food and sweet drinks covered outdoors, seal trash cans, avoid wearing strong perfumes, move slowly near hornets, do not disturb nests, and if nest near home poses danger, contact professional pest control for safe removal, and people with known allergy should carry epinephrine auto injector.