I actually removed some of the tops of the plants to allow more movement on the top, and they seemed to respond to that. More importantly, I bought some pellet food that doesn't sink. That way, I could open the tank and put the food in, and by the time they were through hiding from me the food was still floating. They are still very wary of me and rush behind plants every time I walk by, but now they eat and they seem playful when they don't know I'm watching.

My only question now is, how many should I have? Is a group of 3 too small?