so i have 4 cl's in my semi planted 55gln tank which is my community tank more or less. they are all about 4-4.5" & have been a fat and happy group for over a year since ive had them. at first they were out and always active regaurdless of time o day or light ect. and now it seems the only come out at night. ive tried bribes of shrimp and other pieces of their fav foods and if they do come out its still only long enough to grab the food and hide again. have my guys become fully nocturnal, or is there a reason im missing for this behavior? the only fish in the tank that are of size is my 1 bristle nose male @5.5" & a few smaller baby bn plecos around 2-3"... please help