Hornets and yellow jackets are types of wasps, which are in the same family of insects (Hymenoptera) as bees and fire ants. Wasps can sting a person repeatedly without losing their stingers, and reactions can vary from minor to severe.
Wasp stings cause different reactions in people:
Wasps are usually more aggressive than bees. Yellow jackets cause the most allergic reactions.
Home treatment is usually all that is needed to relieve pain and itching from minor reactions. Severe reactions require emergency medical treatment.
WebMD Medical Reference from Healthwise