For some reason my axolotl can catch food. He is about three to four inches, in a 20 gallon aquarium and is really vicious at feeding time... Or at least tries to be. Every time food comes over he tries to catch it but misses. It just looks like he is jumping at it. He can't even catch tiny blood worms. It looks to me like he can't even open his mouth but he probably can a little bit because he breaths at the surface of the water when he needs air. What should I do?