Hmm, radio huh? I'll have to try that. I have a stereo system in the room and when I listen to CD's they don't seem to notice at all. Maybe if I put it closer to the tank. I can try one of those cheap little submersible filters for a waterfall but I don't really like the idea of keeping one in all the time because I feel like there would be places for bacteria to build up.

As for the whole starving them thing, I've tried it already! They do seem more alert and will be more likely to come out when I wiggle my finger at them but other than that, not much difference.