hmm well I wouldn't go for the stress thing strictly based on age--cause my snake isn't young, he's um around 7 years old.
I was also thinking--you know how they say that if you put certain reptiles in warm water, it makes them go to the bathroom? well when I clean out my snake's tank, I put him in a bucket of lukewarm water. It was a habit I got into when he had mites, and now I figure no reason not to, it'll get him clean if he's happened to take a crap and crawl in it before I cleaned the tank out.
anyway maybe thats why? but I don't put him in lukewarm water, I put him in like, I dunno, cooler water but not too cool. and he doesn't go to the bathroom in the water, he waits between 1 and 3 hours
I think he does it just cause he hates me. he's laughing about it on the inside, I know he is.