50,000 of them?

Today was the day to empty the compost bin and spread it on the vegetable beds, before the torrential rains hit us yet again.  It's good stuff, although obviously not as friable and well-rotted as Monty Don's.  So if Darwin reckoned an acre of garden soil should contain more than 50,000 earthworms, how am I doing?  He said "Their chief work is to sift the finer from the coarser particles, to mingle the whole with vegetable debris, and to saturate it with their intestinal secretions...." so I'll leave them to it.