Field Notes
The Norway rat is not a subtle pest. Where a mouse sneaks, a rat bulldozes — burrowing under your foundation, chewing through pipes and conduit, and leaving behind destruction that can run into thousands of dollars in repair costs. This is the rat behind most urban and suburban rodent problems in North America, and it brings genuine public health risks with it: Leptospirosis, Rat-Bite Fever, and the historical co-starring role in the bubonic plague (via its fleas) are not exactly minor charges. If you’re seeing rats during daylight hours, that’s a sign of a large, established population — nocturnal by nature, they only come out when crowding forces them into the open. Do not wait on this one.