So yea bad me, owner of houdini fish apparently. Just gave me huge scare. Looked at his lil tank he's always at the front and everywhere and checking out me and everything. But he wasn't there or anywhere in the tank. I totally panicked. Looked all around the outside of the tank. I've heard they can jump and always kept lids on. His lid was on but been having probs with new heater going bad i think? anyway left the back teeny lid pushed back a lil to see the heater light better. water high almost flush with wall between filter/heater area and tank. teeny hole slot above filter area. So that's where he was. teeny area where cups, nets, lids, etc won't even fit back there. had my fingers in trying to coax him into hand with stuff. He was afraid wouldn't come stayed in bottom of filter for quite a while. Finally got fingers under him slowly and he jumped back into tank. Whew. He seems okay thank goodness. My nerves so frazzled! We had peacock gudgeon long time ago that loved to jump into filter even with lid and everything so thats how i knew to stick finger in there see if he was in bottom. Now i'm worried about lil air hole/slits in the lid. He's so tiny strong and curious he can get anywhere apparently