im not sure if theyve only lived in a crate that when given their freedom they will know how to get home, i would at first, just let them out in the barn and keep them hungry until they return, and do it in the daytime cos if they get lost at night theyl be much harder to find.
i lost a kitten once overnight, then next day i walked all round the village (mousehole, lovely
) dragging a smelly work jumper on the floor, an hour later the cat was home.