How can I tell if a gopher dug a hole in my yard?

Definitely not a gopher. They make holes more like 12x12. Probably a mole or chipmunk. Is it near a tree or in the middle of the yard? Definitely not a gopher. I would think it is a chipmunk or ground squirrel. Same thing. They don't dig a lot of holes. Try this. Put on rubber gloves. Take Juicy Fruit gum and roll up a couple of sticks, long ways so they make nice little rolls. Toss them in the holes. Most furry little animals don't have the saliva to break down the gum and they either clog up their mouth or intestinal tract.