how big are they?? mine used to always hide when i first got him... he was between 6 and 7 inchs... now he is just over 10 inch or so and he's hiding spot is plenty big enough for him to still hide all day, but now he is always out and about... when he gets tired he just goes to the corner of the tank (where i got the pic of him from) so he is always visible... hopefully yours just need time to get used to the tank and get a little bigger then come out like mine... i also have a tiger shovelnose that is almost 10 inches but never ever comes out with the lights on... if you scared him out he freaks til he finds darkness... lol... so it probably just depends on the fish... goodluck