Geese do not have teeth. Specifically, Canadian geese are not threatening to humans because they are unable to cause bite damage due to their lack of teeth.
Canadian geese have a varied diet. They are generally herbivores, but are known to also eat small insects and fish. Because they lack teeth, they are unable to eat any large fish or insects. Canadian geese are known to eat grass, beans, wheat, rice and corn when on land. In the water, geese can derive nutrients from silt at the bottom of a lake or other body of water. Geese can also eat aquatic plants, such as seaweed. Geese will even sometimes eat bread or other food picked from a garbage can or fed to them by humans.
Canadian geese are at high risk from predators. Coyotes, gray wolves, snowy owls, golden eagles, bald eagles, great horned owls, peregrine falcons and gyrfalcons can threaten both adult and more commonly infant geese. Geese, despite their lack of obvious defensive tools, are able to deter predators because of their large size. Arctic foxes, raccoons, red foxes, gulls, ravens, crows, brown bears and black bears all threaten goose eggs or goslings.
Canadian geese are a naturally migratory bird. They inhabit most of Canada during the summer months and remain in the northern United States year round. In winter, the birds migrate into the southern United States where they go as far south as Texas and the Florida panhandle. The Canadian goose breeds during the summer but ceases to breed after migrating in the winter.