- The House Wren song is long and complex, and both males and females sing.
- As the season progresses, House Wren nests can become infested with mites and other parasites that feed on the wren nestlings. Perhaps to fight this problem, wrens often add spider egg sacs into the materials they build their nests from. In lab studies, once the spiders hatched, they helped the wrens by devouring the nest parasites.
- The House Wren is a fierce competitor for nest holes. They will harass and peck at much larger birds, sometimes dragging eggs and young out of a nest site they want – even occasionally killing adult birds.