Patty and I have had a family of (loud) House Wrens nesting in the yard this summer, and it has been a lot of fun listening and watching as they clamor for food.
The wrennettes are voracious eaters, which ultimately causes a big problem because the parents can't keep up with the plumbing.
I noticed that the opening to nest box was getting a large white ring around it, so large that I wondered whether the little ones would be able to fledge.
The answer is: This is common among House Finches, and there is even a term for it. It apparently applies to House Wrens as well.
You can read more about it here. Check out the first bulleted item.It's like Christmas in June, but not at all.
You cannot make this stuff up!