I would have to agree with you. I had a nice breading pair a while back and they would sit and stare at me with there mouth open when sunning themselves. Also they learnd what came in the takeout box and would stare at me wanting food if i had a white box lol.
Many things may be going on, and no it is NOT territorial behavior. Remenbar a wille back I told you the lamp your using its too powerfull? That may be the cause. Post pics of your setup