Finally Thwarted. (We think)

Madman opened the coop's outside door this morning, figuring the pullets had had long enough to acclimate to their new digs.
When I left for work at noon, there were 2 out - one in the old pen, and one wandering around the edge of the garden. (The pullets were under the mistaken impression that they were free-range hens. When they first started getting out of their pen, we'd go to the trouble of chasing them down and putting them back, but we eventually gave that up. They'd be out again before our backs were turned. We got to the point that we'd see a bunch of chickens out and just heave a sigh as we got on with whatever project had brought us outside.)
Madman went out a little later, found six back in the old pen, gathered them up, and put them back where they were supposed to be. He then sealed up the hole in the netting that he thought they were using for an escape route, and called it good.
A couple hours later, there were six out again. He repeated his previous efforts, and this time making the chicken yard so escape-proof that Houdini would have despaired.
When he went out at suppertime, no chickens were out.
Though there were several standing in the chicken yard in a group, glowering at him and the fence...