Beeeeing busy

We have a lovely wild rose that has grown over the fence at the back of the garden, and it is laden with beautiful white single roses. I spent about an hour trying to photograph a bee flying, and not actually on a rose bloom, but out of the many photo's I took, this is the only one that was in focus - unfortunately it is the rear end of the bee!

I was very impressed with the amount of pollen this poor bee was carrying around. I wonder how much more it has to collect before it can go and unload it?