I had a 20 with a very short tempered Raphael catfish, and a land cat with the self preservation skills of a lemming. I did not have a hood on the tank and the cat fish liked grabbing food from the surface. So cat peers into the tank (situated near a table)at the tinfoil barbs and decides to take a swing. The cat fish thinks it's me feeding and lunges at the land cat. Land cat cleared the room without touching the floor and to this day 12 years later won't go near any tank.
I love cats but occasionally their stupidity shocks me.