Well, they do eat grubs and other insects under the turf. I wonder if they come to the surface to let more air get into their tunnels. Or maybe just to breathe?
My solution to moles has been to just stick the hose down the holes whenever I see them. The moles think they have tunneled into a swamp, and go over to my neighbor's house. (that's my theory, anyway)
Since I've gotten rid of most of my lawn I have hardly seen a mole hole, though. So, long term, eliminate your lawn and you'll see less mole holes.
