From the looks of the structure that is an electric or gas fireplace.
In either case it will be flat on top and the roof portion covers an opening that extends down around the insert.
It should be attached to the wall, and the top of the sides, with cap plates attached to the brick. There may, or may not, be a piece of plywood that covers the top of the opening under the framing.
In a perfect world the bees will be attached to the top or the framing across the opening. Worst case they will be down inside the walls around the insert.
The framing should be a triangle of 2X4s at each end and either another or a single rafter down the center. You may be able to get a side off to get access for an inspection, but if you remove the top it will be all but impossible to get it back without re-roofing it to prevent leaks.
Two handy tools for me are a stethiscope and a box nail puller.
I would open the side away from the entrance and have a look see.