Yep, my Tinka does it too. When I take her out to potty, all she wants to do is scrounge around the ground and find something to munch on. She will eat grass, dead grass, dead or alive plants, seeds from the trees... At first I thought she was just looking for places to potty, but then I realized I was standing outside waiting for my dog to finish grazing!
My mini-Schnauzer doesn't do this... only my Yorkie.
omega