Black bears are opportunists who feed on a wide variety of plant and animal material, although from eighty to eight-five percent of their diet is derived from plant matter, while insects make up a large part of the remainder. Bears eat plants and vegetable matter throughout the growing season, including grasses, clover and the buds of hardwood trees, fruits and berries, and whatever nuts might be available in its environment. The black bear supplements its diet with insects such as ants, bees, caterpillars and grubs. Black bears are not efficient predators, generally preying on easy kills that happent to come near them, such as birds and small animals. They will also eat whatever dead animals they might come across, even decomposing meat. When hungry, they are capable of young deer and moose. There has never been a documented case in Maine of a black bear consuming any part of a human being. There is only one recorded case of a black bear causing the death of a human being, and that occurred in the early 1900s when someone entered the cage of a captive animal.