Bert is the first rat that ever has popcorned for me, well Joshu might have a couple of times but he was more into the cuddling thing. Bert popcorns EVERYWHERE, especially when I'm typing. He likes to popcorn ontot he computer and hit the power button, then hit the enter button turning my computer off if I don't pay attention to him in time. He has done this 4 times earlier today, usually I can catch him before he presses enter.
Bert is so ferocious. He will waggle his head around frantically like a dog, bouncing up and down and pounce my hand. He will also bite, but never hard always play bites that don't hurt at all. If he gets even close to letting down or pinching I squek and he stops XD