I have 11 dwarf cory habrosus in a 60l tank on sand. I initially got 8 of them in 2016, but they regularly breed for me and some young survive naturally. They used to be real brave, out and about wriggling all the time, but in the last year they have gotten shier and shier. Six weeks ago I had to move them to a different tank and as a consequence they have become crazy afraid of me - like if I enter the room 10 feet away they explode towards their hiding places. I never get to see them unless I go ninja mode. It's weird because there is an endler and 21 ember tetras in the tank as well that are all over the place as dither fish, and yet the cories are still pusillanimous pansies. Any advice to return them to their former brave selves? My only thoughts are buy 6 more, or try to raise some more young, or buy a dither bottom fish like a Brochis - (no idea if they are good dither fish). Any thoughs about what might work?