Before you jump to the conclusion that your cat is expressing the following behaviors due to age, make sure with your veterinarian that your cat is healthy. These behaviors are also an early sign of illness in many cases.
Solution: Get your senior cat’s attention by buying new toys, treat them to a few minute full body massage and talk gently and smoothly to them while doing this. This will get them to feel as if they are wanted by you.
Getting lost in rooms or bumping into stuff around the house at night?
Solution: Install some night lights around the rooms that your senior cat is getting lost in; also illuminate the area around their litter box. You should avoid moving furniture around, as senior cats get older they may lose the ability to remember where objects are.
Failure to use litter box?
Solution: Replace your current litter box with a new one, also try to get one on every floor of their living space.
Not sleeping soundly?
Solution: Give your senior cat comfortable sleeping locations, also get your senior cat a pet safe warming blanket to keep their coat warm throughout the night.
Slipping on tile or wood floors?
Solution: Provide carpet runners on those types of surfaces, this will help your senior cat be able to obtain grip more easily.