A friend is renting some fields off a retired farmer. He needed to go and see him and i went along for a ride. As we arrived the guy was feeding a sheepdog which was kennelled outside in a largeish mesh fronted wooden hut.
The dog, who was fit and well, seemed to sleep to one side on pallets and carpets, and on the other side was a large (about say 4 wheelbarrow loads sized) of hard compacted earth. There were rat holes under the hut and clear runs through the grass to a hedge. It was obviously a well established colony, which to be fair to the ageing guy who with failing eyesight did not realize the situation. After a point out to him he was more than willing for me to stake it out and have a go at them with the air rifle.
But could rats be responsible for such a large amount of earth as this, like a giant mole hill ?