What Attracts Black Rats to Your House?

The black rat, or roof rat (Rattus rattus), is a warm-climate species common along the Gulf Coast, the lower Atlantic coast, and the Pacific Coast, including Hawaii. It has a strong preference for warmth and struggles in cold, and it has been displaced from most of the cooler and inland United States by the Norway rat (Rattus norvegicus) — the larger, more cold-tolerant species that actually lives in New Hampshire. That means the ‘black rat’ our own legacy page described attracting to a New Hampshire home almost certainly wasn't one. We say the species is not established here, rather than never recorded, because an isolated specimen carried in on a shipment or moving truck can't be ruled out — but that is the exception, not the pattern the old page implied.

If you're finding rat activity in a New Hampshire home, the far more likely explanation is the Norway rat — a burrowing, ground-level rat that nests near foundations, in basements, and around woodpiles, and that is genuinely common throughout the state. The signs below (droppings, gnaw marks, grease trails, noise) apply to it, not to the black rat. The specific question of what food draws rats and mice indoors is answered in depth at /mice-and-rats-faq, which ranks the actual food sources involved; this page's job is only to correct which species you're dealing with.