I have six 17-week-old pullets: 3 EEs and 3 BSLs. They have begun to fly over our 6 foot block wall. At first I thought they were getting on something near the wall and hopping over but today I watched as two of them flew over after being on the ground. As they get older and heavier will they lose their ability to fly so high? I am trying to avoid clipping their wings unless I absolutely have to. Thanks! (The wall they are flying over is in the background of the pic)