I don't know if you've already clipped them, but I took mine to the vet to get clipped when we moved to a smaller area. i think they may do it at the humane society too.. Maybe you could take one in and have the vet show you how they do it, because yes, they could definawoutely bleed to death if done wrong. An alternative would be to at 3 feet of chicken wire to the tops of your fences.. I had to do this around my vegetable garden a few times.

i ve clipped wings on occasion. all i do is cut the tips off of all the feathers on one wing. starting with feathers close to body. then just go length of wing ending with the last feathers. the last feathers are usually missing abot one third off the length. the first feathers only missing an inch or so. its important to do only one wing or else some of the lighter breeds like bantys can leard to fly with smaller wings. by doing only one they are never balanced, they cant fly unbalanced. theres no blood involved in this way.