Thats a broad question. I free range, with little to no losses. But thats because I watch my birds and I am almost always home. If I were not home, I do not like to let them out. Again, everyone is different. I know the birds in my area, I know the 4 legged and the 2 legged. I have pretty much seen what can be seen here. I know who comes out when and what should not be out when. I know the seasons where animals are out and the seasons when they are not. I know the aerial predators and their schedules (which can vary). I focus on the schedules of the animals here, plainly just to be safer with my flock. Since you do not know what got to your pullet, I would not let then out without supervision, because there will be a risk to free ranging. And unless losses are okay with you, its better to be safe.