What is the primary characteristic of the cluster fly regarding its behavior?

The primary characteristic of the cluster fly regarding its behavior is that it overwinters in the voids of homes. During the colder months, cluster flies seek refuge in buildings, often finding their way into wall voids and attics. They tend to congregate in large numbers in these sheltered areas to escape harsh weather conditions. This behavior is crucial for their survival, allowing them to remain inactive until warmer temperatures return in spring, when they can emerge and continue their life cycle. The ability to hibernate in hidden spaces is a key trait of cluster flies, distinguishing their behavior from that of other fly species.