Our definition of "Spike behaving" is basically anything he is doing that does not involve chasing either of the other two cats or pushing them out of the way so that he can eat their food/look out the window/play with a toy. This time he had jumped up onto the mid height bookshelf and was looking intently at something above Papa Bear's head. Spike's ears stand up and face forward when he shows interest in anything. He likely pays more attention to air movements than the other two, due to his deafness and he really doesn't like having his ears touched. Spike's ears are very firm to the touch and are quite large, in keeping with his overall build. The other two cats have nice soft ears and will gladly sit while we scratch or rub an ear or two.