My dwarf african frog, Kermit, is founs every few hours upside down in the tank. I turn him over and he swims away. Today he doesn't swim away very well. I have put the food right in FRONT of his mouth and he doesn't eat it! I don't know why and it's frustrating me! He is in a 6 gallon tank with two male guppies. Does anyone have any suggestions on what to do?