Nucs that you dont expect a honey crop from, are a great way to learn about the insides of a hive, without disrupting your productive colonies.
Just as an example, the first couple of years we had bees, we pretty much gave up on finding queens when we wanted / needed to. After I started nucs, I made a point of finding the queen each and every time I dug into a nuc. It's much easier in the small colony, and it didn't take long to get pretty good at it. I dont have much trouble finding queens in the larger colonies now either. By digging into the nucs a bunch of times, with the express purpose of finding queens, I learned what to look for, and where to look. As an example, winter is giving the last few kicks here now, and between those kicks we are having some nice days. Last week, on a nice day, I went in to give the first good check of our full size hives, and wintered nucs. It only took a couple minutes each to spot all the queens.
I have come to look at the nucs as a laying queen, in storage. One of the skills I have yet to try, and will be doing so this summer, is learning to mark queens. I expect to do in a couple of them along the way. If I was doing this using the colonies I'm expecting a honey crop from, it could be quite detrimental to honey production. But it wont affect that if I use the queens in nucs to learn this skill. Worst case scenario, I kill a couple along the way, and end up combining some of the nucs.
For me, the nucs have turned into a great learning tool over the summer, allowing me to learn about the dynamics inside the hive, without disrupting the colonies I want to produce honey. For the winter, they are spare queens in storage, and very useful come spring, I've got a couple of dead colonies that will be repopulated using the nucs that wintered well.
