Wasps in the attic (new construction) – evidence of a construction defect?

We have been living in our new building for a little over six months. Today, when I was about to go to the attic, a wasp looked at me. I was a little shocked, the wasp probably was too. But now I'm wondering if the roof is airtight. Or is it okay to have holes through which wasps can fly in? It's a cold roof, built in such a way that you can see the wooden beams under the roof.