Describe the importance of amphibians in nature and for humans?

They are one of the links in the evolutionary chain, their study helps to compose a general system of the origin of species. Amphibians are an integral part of the ecosystem. They participate in the cycle of substances, feeding on insects, molluscs and worms. In turn, amphibians become food for larger relatives, fish, animals and birds. They are eaten by snakes, various canines, pets, hedgehogs, herons, crows, harriers, storks and many others.
The frog is the most accessible and common test subject in scientific research.
For reservoirs, the presence of amphibians in them indicates the chemical purity of the water.