(NewsUSA) - It's the season when welcome mats will be rolled out in homes across America to greet houseguests arriving for shared meals and warmth. While friends and family are welcomed visitors, there are other, less welcome guests who don't need an invitation to enjoy the treats and trimmings the winter offers -- rodents.

These party-crashers generally skip the welcome mat in favor of random cracks and crevices that provide just the inside access they need. Rodent infestations are more than just an annoyance; they can contaminate food sources with feces and urine, spreading Salmonella and Hantavirus. Mice also bring in other pests, such as fleas, mites, ticks and lice, which can quickly spread throughout homes.

Mice are also able to cause significant structural damage to homes. "Mice can bite through walls, wood and even electrical wires," said Missy Henriksen, vice president of public affairs for the National Pest Management Association (NPMA). "The damage to wiring within walls can cause house fires."

As one in four homeowners reports a problem with rodents in the winter months, the NPMA offers the following steps to keep mice from becoming unwanted guests this season:

* Seal cracks and holes, including areas where utilities and pipes enter the home. Fill openings with a material that is inedible for mice, such as steel wool.

* Install gutters or diverts to channel water away from your home.

* Store food in thick metal or plastic containers with tight lids.

* Clean up spilled food right away, and wash dishes and cooking utensils soon after use.

* Keep outside cooking areas and grills clean.

* Do not leave pet food or water bowls out overnight.

* Keep bird feeders away from the house, and use squirrel guards to limit access to the feeder by squirrels and other rodents.

* Use a thick plastic or metal garbage can with a tight lid, and keep sealed at all times.

If you find rodent feces, hear sounds of scurrying in the walls or observe other signs of an infestation, contact a licensed pest professional to inspect and treat the pest problem. A list of professionals and more information are available at www.pestworld.org.