Mason bees are busy here at the mo - since I took this pic the bottom four holes are filled up with new mason bee eggs and sealed up to hatch this time next year.

An interesting fact I read the other day is that solitary bees are much more prolific pollinatiors than the splendid honey bee... 

This is one of Marks 'Solitary Bee Habitats' on the wall for sale at Alby Craft Centre. The buyer will get a real bargain with all those bees in residence to pollinate the garden next year!