Pulled me a noob move over the weekend. She got in to food mode a bit early and prowled the tank for a few days straight. When I dropped the rat in and she immediately went for it. She struck so hard I heard it sounded like it went through the glass. While she's doing her thing I usually take the time to spot clean, change water, etc. I had done this every feeding since I got her and she usually pays no attention to me. Not this time. She spun around on me so fast. Struck and missed, then struck at the mesh top while I was putting it back. It really caught me off guard. I've had her a few months and hadn't even seen a hint of aggression. I don't know if my hand still smelled like a delicious rat or if I just agitated her. Another possibility is expecting more food. The previous owner was feeding 3 mice at a time and I've recently switched to a single rat. Good lesson for me to be more mindful. Unlike my dog, she will bite the hand that feeds her if I'm not careful.