The reproductive characteristics of frogs are hermaphroditism, fertilization in water and oviposition. The breeding time is about the middle and late April of each year. In the process of breeding, frogs have a very special phenomenon-hugging each other. It should be noted that the frog hug is not mating, but a link in the breeding process. Studies have shown that if male and female frogs are artificially separated (that is, there is no hugging process), then even during the breeding period of frogs, female frogs cannot excrete eggs. It can be seen that the biological significance of cuddling is that it can promote female frog ovulation. Generally, frogs lay eggs and fertilize in water. After hatching, the egg becomes a tadpole, lives in the water, and then becomes a young frog ashore. However, tree frogs lay eggs in different ways. The eggs laid by tree frogs with spotted legs are like a mass of white soap bubbles and a mass of cream, which are attached to aquatic plants. The most interesting thing is the Emei tree frog, which lays its eggs on leaves near the water. The egg develops in the egg and then falls into the lake to continue its development. Another example is the piano frog, which sings very sweetly. Before laying eggs, it will build a mud nest and then lay eggs in it. Some frogs belonging to tree frogs don't climb trees, but live in water. Some tree frogs, such as the red webbed tree frog and the black webbed tree frog, have wide webbed feet between their fingers and toes, which can spread their webbed feet from high branches to low branches, so they are also called flying frogs. Besides tree frogs, frogs with suckers include rain frogs and rushing frogs. Among them, rapids are special. They like to live in fast-flowing waters and can quickly cross rapids and climb rocks. The tadpoles of the turbulent frog are also very strange. There is a sucker in its abdomen, which can be adsorbed on the rock to avoid being washed away by the rapids. Toad is a rare frog unique to China. It first appeared in Emei Mountain and was later found in several southern provinces. The snout of this frog is wide, round and flat, and there are 12- 16 pyramid-shaped horny black spines on the male maxillary margin, so it is called mustache toad. The function of these "beards" is still under study. There are many kinds of frogs, but no matter which one, they mainly feed on pests.