My 5 month old Olive is positively crazy about shadows, hers or my foot or a tree moving in the wind. She is also crazy about lights; she chases the flashlight (which is OK I guess) but if the sun shines off my watch and makes light spots ANYWHERE (ceiling, floor, cabinets, cats) she has to bite it. It is bordering on OCD behavior. My angel Cookie also chased lights and shadows, but nothing like this. She's been doing it since about 9 or 10 weeks old. When I take her outside to potty, if the sun is out she can't think about anything but chasing her own shadow. She has lots of fun and gets lots of exercise, but I'm wondering if this is 'normal' weird sheltie behavior. Help!