Which rat is primarily confined to coastal states?

The roof rat is primarily confined to coastal states due to its preference for warm climates and habitats that provide easy access to food and water sources found near coastlines. This species of rat thrives in areas where there are tall trees, shrubs, and human structures that can provide nesting sites. Considering its habits, roof rats are often found in urban areas, particularly in regions with milder winters, which aligns with coastal environments.

In contrast, the other options listed do not fit the criteria for being primarily confined to coastal states. The house mouse is more widespread and can thrive in a variety of habitats, including urban and rural areas. The Norway rat is generally found in temperate regions and often inhabits burrows or sewers, while the sand fly is not a rodent but an insect related to pests associated with the spread of diseases and is not specifically tied to coastal states like the roof rat. Understanding these distinctions helps clarify the preference habitats of different species.