Norway rats arrived in North America with European shipping centuries ago, and NatureServe still classifies the species as exotic in Indiana rather than assigning it a conservation rank. Records near Indiana Dunes National Park, local greenways, and wooded river corridors likely trace back to nearby buildings and disturbed edges more than the parkland itself, since this species thrives around structures and human food waste.
Records spike sharply in June, more than ten times most other months, a pattern that looks more like a single concentrated survey or control effort than a true seasonal peak, since Norway rats breed year-round and stay active through Indiana winters rather than truly changing behavior with the seasons.
Full species profile
