Looks like the Mole tunnels we get in our yard. Sometimes their entrance and exit holes can be good distances away. Last summer we had a tunnel coming from way over the other side of a neighbors yard, through her yard, beneath our fence and into our yard. One day I found a little dead mole in our yard. We don't use chemicals because we have a dog but the neighbor said she was going to ask her exterminator guy to do something so whatever he used must have done the job. I haven't seen any signs of tunnels this year. My mother in law usedto swear that stuffing their tunnels with human hair would get rid of them and it apparently worked for her. She'd collect hair from her hairbrushes and save it in a large zip lock bag and stuff it down in a couple of spots along the tunnels. I tried that once at our old house but only stuck it a little ways down in one hole and it didn't seem to work.
