Well, I suppose there can be sensory degradation in all species as they age. I have a 25 year old bp that I haven't noticed anything like that in, but the snake definitely started feeding less frequently in her late teens. She only feeds 8-10 times a year for about the last decade. I had another her same age that died recently and the pattern was the same. So my experience is that they just don't need the same food intake as they age. I wouldn't be concerned.