Firstly, welcome to the Forum.
Secondly, you almost certainly have a colony of the Tree Bumblebee.
Please take a look at the article I wrote about them which is tucked away in the FAQs part of the About Bees part of they website.
It should answer most of your questions.
Here is a quick link to the article:
The colony will probably die out naturally around the end of July.
Please come back to this thread if you need any further information !