Rat control in Michigan

Norway rats live in burrows in the ground. In Michigan cities, you find them along alleys, under garage slabs, behind sheds, and beneath decks and concrete stoops. They thrive where there is trash, compost, dog waste, fallen fruit or a bird feeder that drops seed on the ground every day. One reliable food source can support a colony for years.

In older parts of Detroit, Flint, Lansing and Grand Rapids, vacant lots, demolition sites and aging sewer lines all play a role. Construction, demolition or a road project nearby can push established rats into new yards almost overnight. On farms across the Thumb and mid-Michigan, rats concentrate around grain bins, barns, corn cribs and livestock feed.

Rats are wary of new objects in their territory. A trap set in a new spot may be ignored for days, and a rat that survives a near miss learns to avoid that kind of trap. That caution is one reason rats take longer to clear than mice, and why patience and placement matter more than the brand of trap you buy.

Rats can survive a Michigan winter outdoors in deep burrows, but they move into garages, basements and crawl spaces when food gets scarce and the ground freezes hard. A rat needs a gap of about half an inch, roughly the size of a quarter. They will widen smaller holes by gnawing through wood, vinyl, rubber seals and even soft mortar.

Common entry points include gaps under garage doors, broken basement windows, floor drains with missing covers, and openings where sewer or water lines enter the house. Rats also travel through damaged sewer laterals and can come up through a floor drain in rare cases. If you see activity in a finished basement with no obvious gap, a plumber's camera inspection can help.

Killing rats without fixing the food and shelter just makes room for the next group. Start with the yard. Pick up fallen fruit, keep trash in bins with tight lids, stop feeding birds on the ground for a while, and move compost into a closed, rodent-resistant bin. Talk to neighbors too, since rats rarely respect property lines.

Next, deal with the rats themselves. Snap traps made for rats, set along runways and left unset with bait for a few days, work well once rats get used to them. Tamper-resistant bait stations are common outdoors, but bait must be used exactly as the label says, especially around kids, pets, and hawks or owls that may eat a poisoned rat.

Last, seal the structure. Use hardware cloth, sheet metal and concrete patching rather than foam alone, which rats chew through quickly. Concrete footings or wire mesh buried a foot or more around sheds helps stop burrowing. Rats under a house often mean mice are getting in too, so seal for both.