go the pet store and see if htey will sell you a baby gerbil or baby hampster for the price of a hopper rat.

most bp wont refuse a gerbil. its what they eat in the wild.

also. try takign a needle and stabbign the mouse in the skull, dead or alive, if its alive it will be movine and needle through the skull will render it fairly harmless, then put it in the cage and watch. make sure their is no fans on. if my snakes feel ari moving over them they wont eat.

good luck