Are blue bottles (the flies) stupid?

I engaged a blue bottle at work today. Quite apart from my size advantage there was a clear intellect mismatch too. The fizz bang was too predictable in its flight pattern. It quickly became apparent that all I had to do was wait for it to try yet again to fly through the closed window.

But then I got one of my philosophical thoughts. As an individual the fly is clearly stupid when compared to the the human. But as a species, the bluebottle is probably a better fit in the grand scheme of things, causing less environmental impact and breeding more successfully. Which begs the question then, are they stupid?