the other day I bought some feeder fish for a Oscar fish I have and after eating all of them he started staying at the top of the tank and just staying around the filter is he ok I checked and he's not dead the bubler is working so he can't need air did he over eat since he ate all the fish there was 5 is it posibal that the fish made him sick what should I do or is he just being wierd and staying the top of tank sometimes he doesent do it I don't know if it's normal cause he hasent done this before please help.