https://www.nytimes.com/2019/05/20/science/earthworms-soil-climate.html

"The plough is one of the most ancient and most valuable of mans inventions; but long before he existed the land was in fact regularly ploughed, and still continues to be thus ploughed by earth-worms"

http://darwin-online.org.uk/EditorialIntroductions/Chancellor_Earthworms.html