I would place some food all about the house, in places you think they would hide.Small places,dark places and anything other ideas you have, put out there favorite food.At least then they will get something to eat.Then think back to when they got loose ,when was it,where was it,and most importantly was the door closed when it happened.If so keep the door closed and there's a better chance there still in the same room.Maybe try setting a video camera and see if the hamster passes by.If you have any dogs or cats in the house then I'm sorry to say that might hamster might not be around any more.More importantly make sure that the main doors are not left open.And finally put out the house or bed,and fill with bedding.I hoped this has helped you ,and that you get your hamster(s)back soon.