It sounds crazy, but chickens can wear a harness like a dog, cat, rabbit or ferret. It's easiest to buy a small harness and try it on your chicken, but if you're determined to make the chicken harness yourself, you can do it with a needle and thread and some thin, flat nylon cord. Here's how to get you out walking with your feathered friend.
Measure your chicken for the harness loops. Measure your chicken around the base of the neck and then around the chest. The measurement around the chest starts between the wings and goes underneath the chicken's belly. Allow for feathers, but be snug without being tight. Finish by measuring from the base of the neck to the back, and the base of the neck under the belly, for the harness straps.
Cut your nylon cord to your measurements, adding 1 inch extra to accommodate sewing the ends together. You will have two loops, a neck loop and a back loop. You will also have two straps, the back strap and the belly strap.
Take your binder rings and assemble the harness. Make a circle with your neck loop and fold both ends of the cord around the metal ring. Sew or hot glue the ends to the cord around the ring. You now have a neck loop connected by a metal ring.
Take your back strap and fold one end through the ring on the neck strap, sewing or hot gluing the end. Do the same with the belly strap, folding it over the neck strap. The neck strap should move freely through the folds. Hot glue or sew. You will now have two straps hanging off your neck loop.
Cut your back loop in half. Pick up the two pieces, and fold the ends of each piece over your second metal ring. Hot glue the ends. Attach the snap-lock clip to the other ends of the back loop by feeding the remaining ends through each end of the clip and sewing or hot gluing. The back loop is finished.
Attach your back and belly straps to the back loop by folding the back strap through the metal ring and hot gluing or sewing. Fold the remaining strap end over the back loop to form a pocket, and hot glue the end. You now have a harness you can fit over the chicken and snap to close.