It seems peeing and pooping can be a means for snakes to 'unload' stress some times. Getting handled and making them active can encourage them to do this as well, in my experiences, for more than just snakes. I had one years ago that would only go after they were allowed to crawl around alot, so I do think moving and activity can facilitate elimination. I just got five that I transported about 6 hours and about half of them soiled their bags, and those that did were less handled. Where did yours come from in Texas if you dont mind me asking? I am always looking and I am in Texas Post pictures when they get settled. I could look at BPs all day long and good luck with them. Sounds like very nice additions.
*Fila*