Alright, I don't think I know for sure what stress marks are, or what they mean. Are stress marks little black squiggly lines running along the underside of a beardie's body? I know they get black beards, too, but I don't think my Hercules is old enough to grow himself a beard just yet. ;P
The reason I am asking is, Herc will sometimes make these black lines appear and his body will look very dark, so that means he is stressed or angry, right? Well, it only goes on for a few minutes at a time, so I thought it was because I was making sudden movements or something. BUT whenever I take him out to hold him, his black(stress) marks leave and he looks bright and happy. He is already starting to cuddle with me, and he even went as far as to jump back onto my hand after I put him in to go to bed last night. So could this mean he is just really warming up to me? It's just a bit confusing because I have only had him about 2 weeks and I didn't think a B.A. like him would warm up to me that fast, lol. He is also only about 2 months old, if that.
Those are completely normal. They are called stress marks, but despite the name they don't really mean stress. They happen when a Bearded Dragon is cold, irritated, interested in something, and sometimes they just randomly show up just because. At any rate, they are nothing to be alarmed about. A dark Beard is the true sign of stress or upset, not these. These are just common markings, no worries.