Meat, in its broaest definition, is food. In modern English usage, most often it refers to animal tissue used as food, mostly skeletal muscle and associated fat, but it may also refer to organs, including lungs, livers, skin, brains, bone marrow, kidneys, and a variety of other internal organs as well as blood. The word meat is also used by the meat packing and butchering industry in a more restrictive sense - the flesh of mammalian species (pigs, cattle, etc.) raised and butchered for human consumption, to the exclusion of fish, poultry, and eggs. Eggs and seafood are rarely referred to as meat even though they consist of animal tissue. Animals that consume only, or mostly animals are called carnivores.