I have an 18 year old cat who I love dearly, however he will not allow me to sleep at night. As soon as I get into bed and turn off the lights he starts to bellow and scream as if he is dying. He first started making theses sounds whenever his litter box was dirty or when he was out of food. Now it is when I go to sleep and sometimes he makes them for no reason at all when I am awake. I realize he is old, however I don't know how much more I can take. He has also started to defecate in my office when I am not at home. I now shut the doors to keep him out. Could someone please give me some advice. He has a GREAT appetite and is still active. He does not have worms and has regular solid bowel movements. I just need to get some sleep, it is starting to effect my health!! Any and all suggestions are welcomed.