We have a 14 year old cat who is in good health. However, he nearly always misses the litter tray and wees on the floor next to it these days. He doesn't go out very much anymore so is using the litter tray much more than he used to. It is cleaned and refilled very promptly after use. And he is trying to use it but missing. Is it because he's getting older? Does he hate me? He eats and drinks well and is still active and able.