Moles make tunnels under the soil which are noticed because they push up the soil. (Some tunnels are so deep, we do not notice them.)
Another rodent that makes tunnels is the vole. Their tunneling is on top of the soil under snow, but most of the time the tunnels are deep enough in the soil that tunneling is not noticed. Only the quarter-size entry holes are noticed.
Here is our fact sheet on moles and how to handle them: http://extension.umd.edu/hgic/moles Tamp down as much of the tunneling as you can before you set a trap, so that you're sure you putting the trap where the mole will encounter it.
But, keep in mind that moles are beneficial--they eat your lawn grubs and other soil pests. So, if you have moles for a couple of years (they don't stay around too long) it can be to your benefit since they don't eat roots or damage plants.