I have a group of 5 Tiger barbs and they seem to be doing well. However, I’ve noticed that 4 of them school constantly while 1 only schools occasionally. I see him alone more than I see him with them. They’re all relatively the same size but he is one of the two bigger ones (these 2 are only 1-2 cm larger). He isn’t acting lethargic and he eats readily. He’s always exploring the tank checking out the decorations and when he sees the school he either swims back to them or keeps doing what he’s doing. Is this bad in any way? Does he just prefer being alone/doing his own thing?