let me start off by saying that these guys gave me a real scare. the second night i had them in the tank, i looked into it about an hour after the lights shut off and what do i see? 2 clowns on their sides in the corner of the tank. i didnt know what was going on! so i quickly turned the lights on and as soon as i did they woke up. i read online soon after that that most clowns have the weirdest sleep habits. my buddies clown swims up to the edge of the filter and wedges himself up there to sleep to stay outa the current of the filter. ive also read of clowns floating on their side at the top of the tank riding the currents. pretty strange little guys. let me know what yours do.