My melowhatsit fry are in a guppy breeder in my tank. The lid is on, and last night I had 9, this morning there are 5. I can't work out how the 4 disappeared. I don't think they are small enough to get through the little holes on the bottom of the box, and the only way I can see they would have disappeared is if they have died and then the other fry have eaten them. Any other theories?