Red Mason Bees

Well I believe that's what they are.

I've one of those little bug hotels hanging on the side of the garage and all day it's been the subject of a dozen or more bees buzzing about in a very enthusiastic manner.    

Lots of acrobatics going on too so presumably it won't be long before the ends of the bamboo tubes are sealed up with the kids growing inside.

I've attached a pic of the bug house as an extra - I've read that stuff like the pine cones is a waste of time - they serve no use to any beasties.   I'm going to be building a bug hotel shortly so will be reading up on what to fill it with and hopefully get it right.