I was wondering if that might be it... It just seems that air coming out would be more absorbed in the water... but they are in fact very eager eaters. Almost as much fun as when I saw a kuhli loach dart from the bottom of the tank to the top, come out of the water a little bit, and dart back to the bottom with a flake in it's mouth. Or when I saw a ghost shrimp 'walk' upside down on the surface of the water, picking up flakes and eating them, just like it would off of the bottom... Anyway, back to the angels... yeah, they are pretty extreme when it comes to chasing their food.