I have what I *think* is some bees nesting behind my roof soffits. There's usually (today at least, with good weather!) around 1-3 of them buzzing around the entrance that I can see them coming in and out of. I've snapped a photo of one of them when it descended closer to the ground:


My guess was that's it's a bumblebee - but I'm not an expert, so;

-Do they look like bumblebees?
-If so, am I right in thinking that there's unlikely to be loads of them and I can just wait for the nest to die off at the end of this summer?
-If not, what are they?