The Yard

We noticed about a month ago that there were some weird piles of dirt in our back yard, but didn't think much of it. Then we saw a cat in our yard, so we thought it was that. Well yesterday the trail was getting closer to the house and when Brad poked it, it there was a hole. We stuck the hose in it and it went in maybe a foot or more. These are bad pictures because they were taken the next day, but they were holes and you can see on the right that there is 'new' dirt, well dirt that didn't get watered yesterday. Also if we bounce on the ground near the holes you can feel the tunnels, I guess you could call them. I just hope that whatever it is it doesn't come closer.