Hypsiboas frog, Manu National Park, Peru.
Frogs eat untold billions of insects each year, making them economically valuable to agriculture. They also provide a critical food source for birds, fish, snakes, and other wildlife. But the most important contribution frogs make may be their role as environmental indicators. When pollution or other environmental changes affect a habitat, frogs are often the first casualties. These delicate creatures provide an early warning for endangered ecosystems.