Definitely going to need some better pictures ... Can't enlarge them to really even see them they are like tiny little thumbnails ... From what you say I would think that it is possibly some kind of change in the husbandry (environment) and that is the spot in the enclosure that your snake feels most comfortable right now .... Some better pictures of your set up and some info as far as what your temps, humidity, and method of heating is would allow us to help a lot more