This is a really good question. I don't have much experience with BPs (Sherbie is my first one), but I don't think that you can always look at them and know the difference. If they appear to be exploring around and your husbandry is off, I would say that is stress. If it isn't off and it's evening/night time, they may just be exploring. Also consider the feeding schedule too. If it's time for them to eat (and they know it), they'll appear more active...or at least Sherbie does. I hope this was helpful. Good luck!866