Re: Swarm in nuc and closed up, how long before I open the opening
I've had that happen, bummer.
I did a cut out last October and it went to a nearby tree branch after I got them home. I recaptured, they did it again. I recaptured and then put a queen excluder over the hive entrance. They were going to leave again but then didn't, and today the colony is doing very well and is the gentlest of all my hives. It's one of my backyard hives for that reason.
"Rule Three of beekeeping...Never cease to feel wonder"--
Beekeeping for Beginners by Laurie R. King