We have been raising Mason Bees for several years. They are friendly, hard working and don’t sting, at least I have never been stung by one.
My first bee blocks were made of wood with holes drilled out for the bees. Problem with this is they can’t be easily cleaned and the bees can get mites.
I experimented with using plastic straws a few years ago and they work well. They need to be FAT straws, the ones I have seen in grocery stores are too small. I get mine at Cash and Carry and they are about $4 for 400. I know there is a war on plastic straws these days but this is not a frivolous use and does not produce that much waste. These straws get used for at least one year, not one drink. When the bees emerge in the Spring, I replace the old bee boxes with new ones so they won’t have mites. You have to do this right away because the bees will start using the old boxes if you don’t.
from Eric Griswold Johnson Rd