On that basis then, The best SCHOOLERS I have in my tank are rummy noses, they stick together like glue, if theyre not all together then it's only 1 who has departed the group to investigate something alone. This may nto happen in a tank with different inhabitants but in mine it does, my harlequins however done school tightly for the most part (they only group up when the light first goes off,but then disperse once they realise its only darkness)