The days are shorter and the nights, colder. And rodents are locked in an age-old battle with humans: They want in. You want them out.

This past summer, an unusual number of squirrels zipped frantically across the roads. The Portland Press Herald and The Bangor Daily News both published articles this past summer pointing to  “population irruption” or a population spike, particularly with gray and red squirrels, due to an abundance of acorns and last winter’s protective snow cover.

While hard data is unavailable on whether Maine’s rodent population has significantly increased, local pest exterminators caution that when the fall months get colder, squirrels and mice are going to be looking for away into homes and cars for warmth. This is a problem, not just because humans are loathe to share their residences and vehicles with “nuisance wildlife,” but because these rodents can burrow into tight spots, die and cause a stink. Or else they gnaw at insulation and damage electrical wires.

Jesse Richards, owner of Central Exterminating Services said:  “To be honest, we’ve been seeing a boom in the rodent population for the last four years. Four or five years ago, we weren’t handling a lot of rodent work in the area, but now, particularly in the fall, it’s nonstop. Rodent extermination is probably our biggest source of business right now. We’re handling five to 10 rat and mice jobs a week.”

Thomas Swartz, owner of Hot Wax Auto Detail Center in Rockport, has also been getting incessant calls about the issue.

“We’re getting hundreds of cars in with mice nests in the cabin air filters this fall,” he said. They get inside the side panels of the car, up in the headliner. 

“Probably 25 percent of the cars coming in to be detailed have that issue,” he said. “People don’t even know they’re driving around with these nests, sometimes even with dead mice inside, and they’re breathing in all that air. It’s so unhealthy. If you could see some of the ones we’ve extracted out of cars you’d be shocked.”

Swartz said a popular myth to keep mice and squirrels out is to place Bounce dryer sheets in the car.

“I’ve found more nests made of Bounce sheets,” he said.

Swartz said the best remedy to keep rodents from getting into your car is to buy a vial of essential peppermint oil and soak cotton balls with them, placing them under the seats, under the spare tire in the trunk and in any small compartments of the car.

“They’re getting in through the tire wheel, so place some in there too,” he suggested.

Trying to close up a camper or an RV for the winter? Many crowdsourced suggestions coming from camping pages on Facebook recommend putting bars of Irish Spring soap, whole cloves and moth balls inside the camper/RV, whereas others have not had luck with such remedies.

Plug up any holes with steel or bronze wool or clear packing tape to seal up any visible opening into the vehicle. Others recommend Fresh Cab, which can be purchased online or at Tractor Supply.

“They also don’t like walking on crushed gravel,” said Richards. “Park your car or camper on a pad of crushed gravel rather than on the grass.”

To keep them out of the house, Richards said, “Keep your property maintained and manicured as rodents seek shelter in tall grass and underbrush. Look around where your oil pipes go down to the basement and plug up any small holes or openings with insulation foam to prevent these spaces for being entry points.”

For more information click on “How to protect your car from rodents”

Kay Stephens can be reached at news@penbaypilot.com