Home Safe Home?

So out on the loading dock at work we have a concrete slab with a concrete ceiling with hooded fluorescent tube lighting fixtures. Several weeks ago a bird took it upon itself to build a nest on the hood. I don't know how it made this decision, but here is the aftermath.

You can't tell from the picture, but the hood isn't that wide and it fairly steeply curved. I was amazed it got the nest to stick. I was also amazed the babies didn't fall out. Then I realized if these two things could be overcome Then there was no way a cat, snake, or other animal could get to the nest. It's probably the most secure location a nest could be built, from an intruder standpoint.

Oh and that bird's head is like right against the concrete roof.