Fish have been known to jump out of their aquarium environment on random occasions, often landing on the floor and becoming a crispy, jerky-like lifeless body. The hobbyist, wrethced with guilt and anger that he just lost an expensive wrasse, then employs a net like structure over the tank to keep the fish in, even if they do try to jump. Unfortunately, fish can still escape sometimes, especially if their are large gaps in the netting or the material itself has too large of holes. When this happen, the net usually becomes a death trap, with fish getting caught on the net in some fashion, baking under the high intensity lighting. If you want to keep your jumpy fish in the tank, be sure to use nets with smaller openings and close up all the gaps around the edges.