This is a lawn I have been maintaining for about three years now. The lawn was in bad shape but she wanted it maintained on a regular basis. I suggested that she let me renovate the lawn with fesuce and she agreed. Know that I have been mowing this lawn during this the cold season I have notice what you see in the pics. It looks like something is burrowing into the ground and pushing up little balls of dirt. This owner has told me that this happens every year around the fall through the winter but its the first time I have been mowing during this time of year to see it. Im trying to see if anyone knows what this is so I can try to fix it. This customer is very pleased with this renovation and she has a lot of influence in this community. I would be the man if I can correct a problem that has been bothering her for years. Thanks for all your help in advance.