To breed. 繁殖

15. Thousands drop in...
    成千上万只树蛙涌来
16. ..to gather at this newly-formed pond.
    聚集在这片新形成的池塘中
17. They all have an urgent need.
    它们无不有着迫切的需要
18. To breed.
    繁殖
19. This female needs to find a leaf
    雌性树蛙需要找一片树叶
20. and lay her eggs.
    从而在其上产卵
21. The breeding frenzy will only last one day...
    这场繁殖的热潮只将持续一天

来自《行星地球 第三季 第四集 Planet Earth S03E04 淡水》第 18 行