We usually hook to the back crossbuck of the next goat in front of them. If they don't have saddles then you are limited to tying them to each others collars or halters. Just make sure to tie them in the normal order in which they hike or you'll have a tangled up mess. Well... most likely you are going to have a tangled up mess anyway but at least you'll stand a better chance of sucess if you tie them in the proper order.