An invasive insect known as the murder hornet, which is over an inch long and can kill humans with its sting, has been spotted in the United States for the first time. Murder hornets prey on honeybee hives, decapitating the bees and destroying hives within hours. While they don't typically attack humans, their sting is extremely painful and can be lethal if multiple stings occur. Scientists are tracking the hornets and setting traps in hopes of preventing harm to humans and bee populations in the U.S.