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Is it mice or rats?

The short answer

Droppings are the quickest answer: mouse droppings are the size of a grain of rice with pointed ends, rat droppings are two to three times larger with blunter ends. Sound helps too — mice are a light scurrying, rats are heavier and you often hear a gnawing note with them.

The signs, and what each one tells you

  • Droppings. Size separates the two, and freshness tells you whether this is current: fresh droppings are dark and soft, old ones are grey, dry and crumble.
  • Gnaw marks. Small, paired scratch marks are mice; larger, coarser damage to hard materials is more consistent with rats.
  • Runways and rub marks. Rats follow the same routes and leave greasy smudges along walls and beams. Mice are more exploratory.
  • Holes. A mouse needs a gap about the width of a pencil. A rat needs one about the size of a quarter or a two-dollar coin.
  • Where the activity is. Roof spaces and upper floors are common for mice and for roof rats; burrows near foundations, decks and drains point at Norway rats.

Why it changes the work

Trap size and placement differ, the entry points differ in size, and rats are famously more cautious about new objects in their environment, which is why a rat job often involves leaving traps unset for a few days before they are armed. A technician who identifies the species before placing anything is doing the job properly.

Both jobs have the same core, though: exclusion. Sealing the gaps is what ends the problem. Trapping and baiting reduce the population that is already inside, and on their own they are a subscription rather than a repair.

Also asked

Can you have both mice and rats?
It is less common than either alone, because rats will exclude mice from an area they dominate, but it happens in larger or divided buildings. It is one of the reasons identification is done from the evidence in each area rather than from one sighting.

Companies whose reviewers name rodents

5,287 pest control businesses in the United States and Canada have reviewers who write about rodents. Every listing shows the full rating distribution rather than the average, the share that is one or two star, and whether the owner replies.

Rodents

Read next

General information about pest problems and about hiring, not advice about your specific property. Pest control licensing, wildlife protection and landlord and tenant law are all set state by state and province by province across the United States and Canada, so your own regulator is the current answer. How we read the data.