To build nests, goliath frogs move heavy rocks to create little ponds in the middle of streams, which may explain how these frogs have evolved to be so enormous
Source:
https://www.newscientist.com/article/2213002-worlds-largest-frog-builds-its-own-ponds-using-heavy-rocks/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home