Such as the tree frog, in summer, the male frog chirps to attract the female frog, and the female frog jumps to the tree by the water with the male frog on her back. Then the female frog secretes a large amount of foam in the reproductive mouth and discharges the egg cells into the foam. The male frog on the back of the female frog also discharges sperm into the foam. Sperm and egg cells are fertilized in paomo. Finally, with the foam of fertilized eggs falling into the water. The female frog and the male frog jumped into the water and swam away.