I had one: my most friendly, most beloved, most lovely and sweet EE girl... I could hold, carry, pet. She would fly over the fence. Being young and light, not heavy yet, she could even fly over with her wings clipped.
She stopped after the three little dogs next door got her... she was o.k., just shaken. Well, a couple of weeks ago, she went over into the alley behind the house, I (being "not young and nimble") climbed over the fence and got her back into the yard... and re-clipped her wings, shorter -- the next day she did it again. There was a dog, out of its yard, in heat, with a "pack" with her... well.. we found only feathers later when she didn't come into the coop at dusk.
It broke my heart, but I couldn't keep her in. She was the only one in the flock that did this, while not being the only EE.
I can only say that I have found that clipping the wings stops "most" of them, if done right (At least the breeds I have).
Others will only stop if/when they get fat and heavy; and there are some breeds that are known to be 'flyers' and maybe they will always fly over the fence?
I hope you don't lose them, or that it doesn't cause a call that creates problems for you keeping your chickens ('code enforcement', 'animal control').
Good luck.