this is just a wild theory, but hear me out.
i think some snakes are smart enough to be paper trained,
examples: my ball pythons sometimes use their humidity hides as toilets, another example, i know a person who has a ball python that sometimes when out of its cage for a while will go back to its cage voulentarily if you let it and escaped once and three days later was found... you guessed it, back in its cage.
now that i have examples of snakes showing signs of intelligence heres the theory;
take a snake thats been housed on paper towels as substrate for a while, put carpet under the paper, once a month use one less square of paper towels until either the snake starts going on the carpet or you have just one sheet of paper in the corner that they use, therefor making your life easier.
now another part of my theory wich i think will be the key is when you notice any urine or feces on the paper clean it asap, when you notice it on the carpet "punish" the snake by leaving it there for a longer period of time (an extra day or two).
the reason i think that part is critical is because when my bps use the humid hide as a toilet it makes the feces smell more and i clean it up as soon as i smell it, when its on the carpet i dont notice it until i take the snake out of the cage, and all this is a theory based on my observations so im sure there are flaws, because im only one person and i think too much
give me your thoughts
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jake
my addiction:
2 normal ball pythons (lazlo and izzy)
1 amelenistic corn snake (mazy)


. Now back to the original thought. While I am not necessarily going to knock the fact that reptiles are "trainable" because they are. Now that "trainable" degree is just that...it's only a degree. It only goes so far. The snake escaped, and 3 days later was found back in it's cage? Well, most likely that is due to the fact that the temps and humidity throughout the house is not appropriate for the snake. It found it's way back to the enclosure because that is the only place it could find that has proper temperatures and humidity. Most likely the snake wasn't far from the cage to begin with.