bee hotel

This link says an egg may have been laid & to mark with pen the closed cells to see if they're still closed the following summer. Is it better to wait till next year to clean it,when it's two years old I don't know,this is info from -
Make a Bee Hotel - The Pollinator Garden
"Inside the tubes and tunnels, each cell will have been provisioned with a mixture of pollen and nectar by the mother bee and a tiny egg may have been laid. The egg soon hatches and the larva develops rapidly by eating the nutritious mixture of pollen and nectar. The larvae then pupate. Osmia will spend the next 11 months or so in a dormant state as pupae, inside a cocoon, until they are ready to emerge as adult bees the following spring or summer. Some other solitary species such as Anthophora spend most of this period as fully-formed but dormant adults."

"Identify at the end of the summer any cells that remain in a walled-up condition from the previous year because no young bees emerged. The contents of these cells will be dead and should be removed and destroyed.
Replace drilled blocks with brand new ones every two years. This is done in the summer, after the young bees have emerged. It will help to prevent the build-up of fungus moulds, mites and other pests and parasites."

I wouldn't clean it now. Queen bumblebees have been active for a good few weeks now, especially the early ones. It's possible that there are already eggs laid and it would be an awful shame to clean them out. We have a willow shrub that was smothered in bumblebees collecting pollen about a month ago so they've been busy for a while. They've all been on the mahonia recently and just moved on to the comfrey. Busy girls.

I think bees are not dead. You have to check very carefully to bees holes.

queen bees are active at moment , we have them on the crab apple blossom
think we had a white tailed queen bee making a hole in the soil near them