I recently added 3 Neon Tetras with plans to stock to a school of 12 gradually in my bedroom tank that has two Angelfish (wild type, with the stripes) and the Angelfish went nuts, basically spending every waking moment trying to chase them down and eat them. The Angels are about 7 months old, so they're not fully grown yet, but large enough. I knew better. They didn't have Cardinals in stock and I was impatient. I know they hunt them in the wild as their natural prey, but I have a lot of plants. The good news is, they weren't able to catch any of them. The Neon's were able to avoid them 100% of the time. I've since moved them to my 10 gallon with my RCS, and they're much happier obviously, leaving my shrimplets alone. They can stay there indefinitely. The 55 gallon with the Angelfish has had guppies smaller than these Neons in it, and has always had guppies around the same size as these Neon Tetras, yet the Angelfish have never batted an eyelash at them. This led me to believe that it would be alright to add them, knowing it was one of their preferred foods in the wild. Do Angelfish have pre-programmed DNA to hunt and eat Neons? They must have seen the red and blue and just lost any control they had. I've never seen them do that before. Lesson learned.