They each have their own distinct personalities. Rocky, when not wound up is more laid back then Willie. Rocky is more content to just lay with you and relax where as Willie is like a ball of energy. I call him “psycho” cause he is in constant motion until he is ready for a nap. Once tired, he will also just lay by you. Rocky is beginning to fill out his frame now and thicken up. Willie has been thick for his frame, which is smaller than Rocky, from the beginning. I can’t begin to tell you how great they are with the family and even guests once we bring them in to the house and they see they are welcome. They are completely devoted and loving with us and accepting of welcomed guests. Both boys love to go running with me. I alternate taking each every other run and the one that does not go with me on my run I take after my run to the closed in tennis courts near our house and play ball with him. All I have to say is “walk” and they run to the door and go nuts.