Tunnel Investigation

My paws trotted straight along the wooden backyard fence! Down where the cedar boards met the green turf, a hollow yellow plastic tennis ball was wedged tight beneath a raised knot. Patrol obstacle spotted! I dropped to my knees, wedged both thumbs under the curve, and gave a mighty heave! Pop! The ball broke free, rolling across the dry grass and bumping right into a smooth gray garden stone. I scrambled over, planted one boot on top of the stone, and gave a joyful yip! Route obstacle cleared, and playground sector is safe and sound!