If they think you are their mother, they should stay close to you. Maybe you can let them out in a confined, warm place - like bathroom. Sit on the floor with them and let them explore while you speak in a soft voice. You may even lay your hand flat on the floor so they can investigate it. You could do this a couple times a day for short periods, so they can see you don't try to eat them. When they are a little older you can try offering them treats scattered near you. In time they will climb up on you to look for more.