The quick brown fox

There is a rock wall running the length of our backyard, and a fox's den just beyond the end of it. Normally this wouldn't present a problem, but with all the snow in the last three weeks, Mrs. Fox has been using the top of the wall as her personal highway. Normally this wouldn't present a problem, but our dogs, Sunny and Jack, have some issues with it. Mrs. Fox is brilliant red and very easy to spot against the white, snowy background. The dogs have worn a path from the windows in the sunroom to the back door. They run outside in a crazed zigzag path to the wall and back to the door, then to the sunroom windows then back to the door. It doesn't seem to bother Foxy at all. Oh, did I mention the dogs are labs? And the cardinals are too quick?