The gizzard is a very muscular stomach that is found in birds, earthworms, and other animals. "A bird swallows small bits of gravel that act as "teeth" in the gizzard, mechanically breaking down hard food such as seeds and thus helping digestion." (Solomon et. al, 2002)


  • Solomon, E.P., Berg L.P., and Martin D.W., 2002. Biology Sixth Addition. Thomson Learning Inc., Australia, Canada, Mexico, Singapore, Spain, United Kingdom, United States pp. 664