Our lab mix (lab/whippet? lab/weim? lab/weim/whippet? - we aren't sure) is quite agile and athletic. We replaced our 4 ft stockade fence (which she jumped like a hurdle) with a 6 ft stockade fence to keep her in the yard. Within 12 hours (and several hundred dollars spent), she figured out how to jump the 6 ft. too. She doesn't climb up the fence...she jumps to the top, from an almost seated position, perches like a bird , then makes her way to the ground. From there, she takes off at a full sprint and comes back if/when she feels like it. We live near a very busy street and are worried about her getting hit. I wouldn't believe this if I hadn't seen it and many people, even after seeing it still don't believe it. Suggestions welcome!