We have a year old beardie which we adopted about three months ago after we lost Atlas. This guy used to poop in his enclosure but throughout the summer we would take him outside to soak up the natural sun rays aand he started to use the bathroom on the grass and seems to have taken to the idea that he is suppose to do so only on the grass?? We noticed this behavior when he didn't go for about three days(it was rainy) and when the chance to go outside he went alot on the grass. In fact we can't get him to go in the bathtub? How can we possibly change this behavior, or maybe not change but...alleviate?