If you have reallynice weather (30's or 40's)and then hit extreme cold, they maysit tightfor a day or two as quite often their food supply will also hold up. Get past the twodays, and they must be out looking for food. Quite often they don't care to move too far from their den (are not usuallymiles away) in extreme cold. If you know where some dens are, set-up within a half mile anddo some calling. A call really carries with snow cover.