As a kid growing up on a farm in southern Minnesota, my Dad partnered with someone to start a egg laying operation with about 3000 chickens in a 3 story barn that we had. The raised platforms for the chickens were covered in chicken wire. Thats were they pooped. The rats would tunnel under about 12" of the dry chicken turd, to steal eggs. After we got rid of the chickens, all the poop had tobe shoveled out, and the amount was considerable
As we scooped it out, the rats would be running every which way. My German shepard had a field day killing rats. My uncle also had a .410 shotgun and he was blasting away. It was fun in a weird sort of way. Not sure how many rats were killed.