I recently got a bumblebee at a local show and it is displaying an interesting habit that I thought I would share. I used plant saucers has hides, after i cut out a hole and heated the the cut to remove any sharp edges.
Recently he has flipped both of them over and curls up underneath them. I've tried flipping them back over so they form a dome over him, only to come back an hour later to him flipping them back over to form a bowl with him still hiding under one of them.
He hasn't gone off feed, and doesn't seem stressed out, but its just weird that he likes his hides the opposite way of every other ball i've seen.