So I have I 10 gallon tank, all cycled and 76 degrees, with 1 betta and 6 harlequin rasboras, My betta has no problem with the rasboras, occasionally he will flare a tiny bit if they get in his way and they will swim away with no problem, nothing serious. But recently, all my rasboras have been huddled in the corner of the tank with the heater and filter, There is one or two of them that swim around the tank but they goes to the corner sometimes too. Every night I have looked and noticed that once I turn off the light and they all start swimming around and leave the corner. Today I turned off the light just to see if the would leave the corner when I did, and they did! Maybe they come out at night when my betta is resting because they're scared of him? My betta is super friendly towards me, he will swim the front of the tank to see me and swim around until I leave. I've read rasboras aren't nocturnal, but they're acting as it they are!