Anyone else have fish that do "odd" things?

[fkshiu]

My blue regal does the same thing as yours, Christie, only at the bottom of the tank close to where he usually sleeps. This causes a weird vibrating noise that can be quite creepy if your sitting in the room by yourself not knowing where it's coming from.

My theory is that it's either some kind of defensive posturing or mating behaviour probably to do with seeing its reflection.