I ran into something similar with my year old this week. He's been getting a weaned rat every Monday since I got him a month or two ago and has seemed pretty content. We weighed him over the weekend and found that his big rear end weighs 495 grams, meaning he's due for a bigger meal. He would start to look very "hunt like" a couple days before his feeding and yesterday (two days after feeding) he struck at the air when we turned the ceramic light on for the evening. We thawed a rat and fed him, which he hit and swallowed immediately! Time for bigger rats! Luckily the reptile expo is this weekend, so we can get small rats.