The bald-faced hornet is a long, wasp-like insect. They are often confused with a yellowjacket but can be distinguished by their black bodies and white facial markings. An infestation will often appear in an organized colony of 100-400 insects, which live in a large paper-like nest that hangs from a structure. Known for their aggressive nature, these pests will repeatedly sting any suspected threats to their nest. Stings from a bald-faced hornet are venomous, causing pain, itching, and swelling for approximately 24 hours. Stings can sometimes result in a mild to severe allergic reaction and require medical attention. Because of their aggressive nature, removing a nest can be difficult and dangerous without professional help.