If at first you don't succeed, fly fly again

Madman just came in from capturing the last of the pullets and moving her to the main chicken coop with everyone else. He'd nabbed most of them last night, but this one had evaded him somehow.
This was the second time he'd tried to merge the flocks - adding this year's pullets to our main group of layers. (Read about how it's done here.) He tried a couple of days ago, capturing all the pullets while they slept, smuggling them into the main coop, and setting each one on the roost.
But when we woke up the next morning, all the little chickeny brats were right back in their old pen. They'd found some way to escape and had headed back home...
Since we want their pen for our new group of meat birds, we really really need them out. This time, we're taking no chances. The main coop's door to the outside is closed, and will remain so for a couple of days, until the pullets forget about the old homestead and settle into the new.
There's a reason that the expression is not "A chicken never forgets"...