I somewhat agree with Elliotness .... Sounds like there simply is not enough to convince him it is a meal ..... I would try thawing feeder in hot water then hold the feeders head 1 inch off of a heat lamp bulb or something to make the head warmer than the rest of the mouse's body and then dance it around in front of him with tongs to give it a lifelike appearance ..... You could get a live and offer it to him as well like stated above ..... A picture of him to judge size would also help so we can make sure size of the feeder is correct as well