Something in the attic...

I think that this is a wasps' nest.

I believe that it is empty and (at least temporarily) dormant. Well, I certainly hope that is the case.

I know that it is really a very wonderful piece of construction, and even beautiful.

I wonder how they make such a thing.

It would be interesting to watch the building process, except that in the early stages the watcher would be exposed to many small builders who might not appreciate ones presence.

It's my impression that this object has been in place at least since we moved in here in 2006. I once found a round, free-standing one, really small: about 2 cm in diameter.