Whip1

Clearly, you have never had a substantial mole population in your yard.

They create trails of dead grass throughout your yard that are easily noticed.

Their burrows can be dangerous to walk over. You might trip and fall.

Turf Toes, I've never dealt with a serious mole problem. I have a few small mounds of dirt in the yard, and that's what got me thinking.
Dchall, How big are the moles in Texas?

Moles in my yard burrow in random directions and lift the dirt a couple inches. Their trails can be seen 75 yards away. They go all over the place creating havoc. Windmills and noisemakers do not work. Smoke bombs do not work. Most poisons do not eliminate them. In fact I believe they would be here after a nuke attack that I hope never comes. Castor oil seems to help but getting applied everywhere is tough.

I have had a few mole problems in recent years, but this year was 10 times worse than previous years. I think it was a combination of factors. My soil is getting healthier and has more earthworms that moles eat (I haven't seen any grubs). And, I have heard that they are worse because of the drought. Any area that is irrigated will have more food for the moles and have softer soil than the surrounding parched earth (I have undeveloped land on 3 sides of my back yard). I have tried repellants, spike traps, and castor oil mixture, but have done little to deter the moles.

To answer the OP's question. YES, they can do major damage to your lawn. The attached picture is not of my lawn, but shows what the gras looks like, even after the mole hills have been leveled out.

Here is a link that might be useful: {{gwi:121515}}

tak2w, I've never seen mole damage like that, and that's why i was asking. Why do I get the feeling that I'm going to be here in the summer asking for help with moles?