Hantavirus Information:How to Determine if Mice Are Infesting Your Home!

Hantavirus: 
Some Common Signs of Rodent Infestation

Do you think you have rodents infesting your home, barn or workplace, but aren't sure?  Here are some common signs that you may have a rodent problem.

Deer mice droppings in drawer (3225 bytes)You see signs of rodent nests. Rodents tend to build their nests from materials that are soft, fuzzy, or warm. Among common rodent nest materials are shredded paper, bunches of dry grass or small twigs, fabric, and furniture stuffing. Rodents will nest wherever safety from enemies can be found close enough to food and water, and they prefer places that are relatively quiet. Inside buildings, here are some places to look:

You find food boxes, containers, or food itself that appears to be nibbled. Look for droppings nearby. Rodents can chew through plastic, so plastic bags do not make safe food storage containers.

You find signs of rodent "feeding stations." These are semi-hidden spots where rodents eat food they have collected. At these stations, rodents may leave larger-than-normal amounts of droppings/urine, plus remnants of a variety of foods (such as nut shells), bits of plastic or paper, and cockroach carcasses.

You find evidence of gnawing. To get to food, rodents will gnaw on almost anything that is softer than the enamel of their teeth. This includes such things as wood, paper board, cloth sacks, and materials even harder than these. Because rodents' teeth grow continuously, they must gnaw to keep them short. That may help to explain why chair legs or similar surfaces show gnawed spots or tooth marks in rodent-infested places.

You notice an odd, stale smell. In closed-up rooms infested by rodents, you will commonly smell an unusual, musky odor.

You see a mouse in your house. However, this doesn't happen very frequently! Why? Rodents are normally active at night, and generally avoid humans. If you have rodents, unless the infestation is large, you may never see one.

Workplaces can also make good rodent homes.  Warehouses, restaurants, and the like are obvious places to look because food may be plentiful there.  However, rodents can infest office buildings, too.  Once again, look for droppings in protected places like closets, storage rooms, or inside boxes.

Want to know what droppings look like?  See the bottom of this page!

Deer mouse nesting in old chair (4450 bytes) large view (Click on image to view as pop-up window)

You see signs of rodent nests.  Rodents tend to build their nests from materials that are soft, fuzzy, or warm.  Among common rodent nest materials are shredded paper, bunches of dry grass or small twigs, fabric, and furniture stuffing.  Rodents will nest wherever safety from enemies can be found close enough to food and water, and they prefer places that are relatively quiet.  Inside buildings, here are some places to look:

You find food boxes, containers, or food itself that appears to be nibbled.  Look for droppings nearby.  Rodents can chew through plastic, so plastic bags do not make safe food storage containers. You find signs of  rodent "feeding stations."  These are semi-hidden spots where rodents eat food they have collected.  At these stations, rodents may leave larger-than-normal amounts of droppings/urine, plus remnants of a variety of foods (such as nut shells), bits of plastic or paper, and cockroach carcasses.
You find evidence of gnawing.  To get to food, rodents will gnaw on almost anything that is softer than the enamel of their teeth.  This includes such things as wood, paper board, cloth sacks, and materials even harder than these.  Because rodents' teeth grow continuously, they must gnaw to keep them short.  That may help to explain why chair legs or similar surfaces show gnawed spots or tooth marks in rodent-infested places. You notice an odd, stale smell.  In closed-up rooms infested by rodents, you will commonly smell an unusual, musky odor. You see a mouse in your house.  However, this doesn't happen very frequently!   Why?  Rodents are normally active at night, and generally avoid humans.   If you have rodents, unless the infestation is large, you may never see one.

Remember that not all types of rodents carry hantavirus. Neither common house mice nor common rats have been associated with HPS in humans, for example.  Yet because it can be tough to tell just what kind of rodents you have, play it safe -- clean up the infestation and rodent-proof your home or workplace.

Read our Meet the Rodents page to learn how to identify the rodent species that carry hantavirus in North America.

Size of Deer Mouse and White-footed Mouse Droppings Compared with the Droppings of Other Household Pests:  Close to Actual Size

Size of droppings of deer mouse and white footed mouse compared to that of other common pests

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Related topics

Facts about Hantavirus  

Ready to clean up a rodent infestation?  Visit "Tips for Preventing Hantavirus: Cleaning Up Rodent-Infested Areas" to learn how to do so safely.  

Looking for more details on identifying a rodent infestation?   Rodent-Proofing Techniques.  

This page was updated on 15-May-2015