Is there a trick to getting these on? I found it very difficult. I did a hen and three week old chicks... not good. 8 hens, a roo and 19 chicks to go... I don't think this is a good idea! I must not be doing something right (I hope)! I considered zip strips and velcro but didn't think I could mark them well. The spirals come in many colors and you can do right/left leg too.