Bee's nest

I'm afraid apart from knowing they bizz about, can sting you (then die) if provoked and make honey I am ashamed to say I don't know much about Bees. I'm in the process of renovating a bed and I was in the process of yanking up an ancient scrambling Contoneaster which has seen better days when a Bee landed between my feet and disappeared into the Cotoneaster. A couple of seconds later another Bee appeared/disappeared in the shrub and then another so I didn't need to be Einstein to realise I had come across a nest. After watching for a few minutes I satisfied myself that this was indeed a nest and was a "hive of activity"!!!!!!!!!
I know nothing about underground Bees nests and was wondering if someone can tell me when I will be able to continue to clear the bed and get rid of the shrub. I have no desire to disturb the Bees or get stung for that matter, hopefully I won't have to wait too long before I can start clearing again.

 

I also have 3 under ground nests one which has been dug up but the bees and are still using it, so i will be watching this thread for info, thank you silu for post it