Telltale Signs of Mice

By Chris Williams on January 28, 2013.

mouse poop or droppings can determine if you have an active infestationSomeone asked me the other day, “How do I know if I have mice?” It’s true that mice are not often seen (at least in low numbers) because they are active at night. They do, however, leave behind evidence of their existence…if you know what to look for.

Mouse droppings

Mouse droppings are usually black and about 1/8 to ¼ inch long. They are thicker in the middle, narrowing at each end. A single mouse will deposit about 70 droppings a day randomly during its travels. Fresh droppings have a putty-like consistency while old droppings are brittle.

Mouse nests

Mouse nests are small piles of whatever soft materials are available like shredded paper, insulation material, string, chewed leaves, pillow stuffing, dryer lint, etc. You may find hoarded food (like stolen pet food or bird seed) in a mouse’s nest. And you may find mouse droppings nearby, but usually not in the nest itself.

Mouse nests are constructed in hidden, dark places that are usually within 30 feet of a food source. Kitchens are a prime location for mouse nests and they are usually found in the back corners of kitchen cabinets, behind cabinet kick plates or in wall voids, in and under stove pan drawers, and in warm places near electrical motors like behind dishwashers or refrigerators.


Mice chew a lot on most anything—plasterboard, wood, vinyl siding, and fiberboard. They’ve also been known to chew on electrical wires in attics, causing fires. They will chew the edges of an opening to make it larger so they can get into tight spaces. If a mouse can find an edge or corner that it can bite with its teeth, it can gnaw an opening big enough to get the rest of its body through.

Rub marks

Because they are creatures of habit, mice travel the same routes all the time. The oils in their fur leave dark, greasy smudge marks where they brush against walls or objects. If you find mouse “holes,” or the openings they are using to get into spaces, you will find that the holes are edged with dark rub marks from repeated use.


You may hear scratching or scrambling noises in attics, wall voids, under cabinets, or in other areas where mice are nesting.


This is harder to describe but once you smell the odor of mice, you’ll find it’s very distinctive. I don’t find it to be unpleasant myself. Some say it smells like stale popcorn.


You may find this sign of mice in very dusty areas like crawlspaces or garage floors. Look for mouse footprints, along with tail drag marks.

If you’ve noticed any of these signs of mice in your home, give Colonial a call. Our trained pros can conduct a thorough inspection for mice. We are experts in rodent removal, mouse control, and we can even mouse-proof your home to keep mice out.



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