The American Bullfrogs are a highly reproductive aquatic species that are native in central, eastern United States and Southeastern Canada. This species was first introduced to western America as a food source (frog legs!); since then it escaped aquaculture ponds and have spread widely. Bullfrogs lay up to 20,000 eggs each season, and are voratious predators: they eat anything that fits in their mouth. Bullfrogs can be recognized by the large round eardrums behind its eyes.