I have, on a couple of occasions, used a nail. Sometimes that's the only thing that will work in a given situation. However, in most of my hides in trees, I have used either large paper clips that I've twised into an S hooks or old metal shower curtain loops. I particularly like the shower curtain loops. They're large enough to fit easily around a branch without impeding its growth. They're strong and they'll last forever. -- ORR