Out of 18 spoiled rotten hens, only one of mine thinks she is a bird and will fly over short or tall fences. Yesterday my Cleopatra, an EE, was found in the garden over the 5 foot fence. We have learned that for us in chicken fencing the key is to not have a solid top wire for her to land on. We put up another two feet of bird netting on top and that does the trick. Her MO is that she likes to land on top and then fly down, if she can't see a wire to land on she won't fly over a taller fence. Her sister EE Barbra doesn't try to fly, and weighs a lot less due to less muscle. Cleopatra follows me around the homestead like a dog and logs several miles a day!