4-5 years ago we redid our backyard. we killed the old 'grass/weeds' with chemicals and then layed 6-24 inchs of garden soil everywhere. we rolled it with one of those small rollers you add water too from home depot and seeded. we rolled it the next spring too.

about 1-2 years later we noticed these small bumps in the ground. they are about the size of a golf ball. and its a lump of dirt and its kind of still under the grass. it got worste and worste and now im lucky if i dont break an ankle back there. its completly destroyed.

only next year did we find evidence of moles. we saw the huge piles of dirt everywhere in the yard. luckily they seemed to now be gone. i dont see any other piles? and they have stayed in the back yard.

3 years ago we soded the side yard. there was not much growing there so we scraped the top layer with a tractor, and again put some new garden dirt. we didnt do any rolling in this yard

this year im starting to notice a few of those lumps. what is up with that?