Look for tracks and hair. Leave the dead ones there for a while, and place a foot hold, steel jawed trap just inside the hole. Make sure it is secured; you don't want to lose the trap. The critter probably will be back for seconds. It will be hard to endure the smell, but the longer they lay there, the more likely you will get the critter.
Dispatch it from a distance. You do not want to get bitten.
Good Luck,
Rufus