Every time my BP relieves himself he does it in the same spot. I have one of those tree stump hides with a hole in the front for the snake to enter. He'll go in there, do his business and leave. One day I was just watching him - I saw him come out of his favorite hide, crawl all the way to the other side of the tank, enter the stump and situate himself so that his little head was sticking out of the hole in the stump just looking at me. I remember thinking: "are you doing what I think you're doing?". He was looking at me as if he was saying "do you mind?". Shortly thereafter he exited the stump and returned to his hide. Left me a nice present!

Here's a picture of his stump - only this time he's just climbing through it:

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1.0 Ball Python "Aragorn"
1.0 Kenyan Sand Boa "Gimli"
0.1 Australian Cattle Dog/Pointer "Kira"