Hi. I have only 4 panda corys now. Thing is I read the are schooling fish but mine are never togehter and always off on there own. Also I read they like to sleep in a pile together, well ive never seen any of mine slepp There active from when i wake at 6 am until I go bed at midnight, even when tank lights are off. Are they actualy active fish anyway? Also why do they not group together?