If you have aspen in the viv, you really should take your snake out first, so that he doesn't eat the aspen too. It can kill them. If you put a papertowel over the aspen, he could get the mouse and take it to the aspen under the paper towel. If you don't have something to put him in, if you are careful and watch him, you could just put him and the mouse on a couple of sheets of paper towel right on the table or counter or wherever, then when he is done, just gently lift him up and put him back in his viv, or you could take both sides of the paper towel and use it like a sling to lift him and then put the paper towel in the viv with him in it. You really can use anything to feed them in. The list goes on and on. Plastic tupperware containers, cardboard boxes, shoe boxes, pots and pans, dishes, paper bags, just use your imagination. The snake doesn't care where it eats.