My ball will not eat prekilled .. he absolutly refuses. HKe goes out of his way to ignore them. I had to go up to a town that has a good sized pet store to get the frozen mice, 4 of the medium mice for $9.00 .. or something like that ... 3 hours of my time and $20 worth of gas just to try it out, and he refused. From what I have read, Balls are picky eaters, and from what I have seen/read .. that seems to be a true statement.