kitty old timers

Rod, a behavior change in an older pet may be sign of an underlying medical condition that is developing.  While 13 is considered geriatric in cats, "senior moments" usually come a bit later.  A physical exam at the vets would be a great place to start to see if there is anything medically going on.  An ear infection or fleas can cause odd behavior as well as something more serious like Hyperthyroidism.  A complete blood work up would be very helpful to see if there are any other issues surfacing like early kidney disease.  Let us know what you find out!