I agree with the others.  Sounds like hyperthyroid to me.

I went to the vets last night and they did blood workup, urine and
blood pressure + exam.  Nothing wrong with him.  No medication
prescribed.  The vet said it may be senility and the only way to test
would be an MRI.  Not recommended at this time.  She also ruled out
thyroid.

So, it is a behavioral problem.  She said to call back in a week if any
change in behavior.  So, I don't know.