I've seen some yard/landscaping threads on this forum before so maybe some of you can help me.
Over the past couple weeks I started noticing these "holes". They only go about 1-2 inches deep and then just stop. Since they are really shallow I know it's not moles or anything. Well, being as this was in the back of my back yard, I wasn't too concerned. The problem is that these "holes" have spread through over half of my back yard and are really starting to tear stuff up. It gets worse everyday and I think it's happening at night time. Any ideas as to what's causing these? Here's some pics to show.
This is what it's doing to my yard and it's spreading
