Bacillus thuringiensis (Bt) is a group of soil microbes that are used to control certain insect pests. Each type of Bt makes a unique protein that is toxic to some insects, but not all. Some plants, such as corn, have been genetically engineered to protect themselves by making their own Bt proteins. Watch the video to learn more about how Bt works on insect pests, the risk to people and animals, and how you can keep your risk low.