I was all ready to chime in that my guys definitely prefer mice, but today I fed my younger two worms out of my yard. I left the dirt/mulch in a shallow container with dozens of worms and these two really went after them with enthusiasm! It was fun to watch. They'd poke their head into the "dirt", root around, then you'd see their body tense up and they'd emerge with a flailing worm hanging out of their mouth. When I used to cut pieces of night crawler and serve them with pinky pieces they'd usually go for the pinky pieces first. I don't think it could have been the movement of the fresh earth worms, because they had to hunt most of them sight unseen. Pretty cool, tho May just change my mind about feeding worms.... at least for a day or so until I have to clean the nasty poo out of the tank