Charlotte, when we moved into a log home we noticed that the tiny, long spaces between logs had little bees coming & going in the spring; I was to learn these were mason bees. They'd long ago adapted to using the house for egg-laying & hatching. They were surviving the natural way, in droves! When we had to add siding & insulation over the logs to keep our house warm, I started with bee boxes with "shelves", the kind you unscrew the shelves to release the bees, which I continue to use now. I don't bring them in, just leave them out all winter, but do clean the "runways" once they've hatched to clear out any mites. Every few years I start over with new wooden shelves, but keep the bee box. My point is it doesn't have to be complicated with removing cocoons, etc. I lose some to mites, but most hatch in April.
Charlotte, when we moved into a log home we noticed that the tiny, long spaces between logs had little bees coming & going in the spring; I was to learn these were mason bees. They'd long ago adapted to using the house for egg-laying & hatching. They were surviving the natural way, in droves! When we had to add siding & insulation over the logs to keep our house warm, I started with bee boxes with "shelves", the kind you unscrew the shelves to release the bees, which I continue to use now. I don't bring them in, just leave them out all winter, but do clean the "runways" once they've hatched to clear out any mites. Every few years I start over with new wooden shelves, but keep the bee box. My point is it doesn't have to be complicated with removing cocoons, etc. I lose some to mites, but most hatch in April.