I'd be curious if there was a soil fungus there or even an odd cowpie or something.

Circles, the circles are haunting me. Animals, bugs and now even the grass. What's next? You are going to tell me the whole Solar System is going in circles?

Run

Could be a landmine. Careful.

I read somewhere that some plants grow in a circle when it is extremely dry over a long period of time. That way they their roots can get the most amount of water from the soil.