Since you don't know just where they are roosting, I would say to set back and observe from a distance. It would be hard to try and hunt them on the way to the roost, when you don't know where they are roosting. On the other hand, if you know the general vacinity where they are roosting and which direction they are coming from then you could set-up to intercept them headed to the roost area.Not sure just what your terrain is like and what they are doing during the day. during the day are they hitting the open fields, high country, staying in bottoms, or timber? Figure where they are feeding, timber, grass or crop fields, and intercept them headed back to the timber.Lot to know, to know what to tell you, but there are a few ideas. Knock'em dead.