I love when people say fish try to jump out of the tank. Its simply not the case. Fish swim in the tank and sometimes they get startled and swim fast to the left/right/up/down. Sometimes swimming up causes them to breach the surface of the water and us silly humans think they trying to escape the confines of the tank
I know that, but it doesn't make much difference when your fish ends up on the floor.
Obviously no fish trys to jump out the tank, intentionally.
They just seem to freak out a bit when the lights out.