Gliders always do their duty when they first wake up too. If they are just waking up, this could be why and sometimes they will do it to mark you too. If they`re just waking up, set them down and let them do what they have to do and you should be all set for awhile.
You never know, one may want all your attention, could be jealous (possibly), just make sure u pay the same amount of attention to both, don`t favor either of them. If you take one out of the cage, you should take them both out, don`t leave one in the cage, this could cause big problems.