http://www.bing.com/images/search?q=...2D1126&first=1
Here is an image of a Black Footed Ferret.
On our last day we were behind a ranchers barn and in both his cow yards (not pastures) it was fence to fence prairie dogs. For some reason he let it go and the dogs were out of control. We shot and shot but couldn't get them all because some would go in their dens and get missed. And they would stay to repopulate the town.
All those mounds and holes would be tough on the cattle. If it was mine I think I would have poisoned and bladed it flat and then reseed.