Rise in rodent population proves vexing to homeowners

NEWBURYPORT – Dave Herbert of Essex Pest Control has seen his fair share of mice during his 32 years in the business. But nothing compares to this season.

The number of calls regarding mouse infestations began rising five years ago, he said. Then, after increasing by 20 percent each year, he suddenly logged a 40 percent spike in 2011.

“It’s definitely the worst we’ve seen so far,” said Herbert, who operates the business with his father, Dick Herbert. “We used to see more peaks and valleys. If someone called in the summer, it would be unusual. Now, we see it all the time.”

His observation was backed by Sheila Haddad of Bell Laboratories, a Wisconsin-based manufacturer of rodent-control products.

Dave Herbert of Essex Pest Control puts mouse traps under sinks, among other spots around homes, where mice can squeeze through gaps around pipes.
“From Virginia to Maine, it has become a big problem,” said Haddad, the company’s regional manager for New England and Canada.

Some residents who in the past may have seen an occasional mouse in the basement have had to ask for professional help this year, Herbert said. In December, he helped a family on High Street in Newburyport deal with an infestation that over the course of a few months had spun out of control.

The family had begun noticing the typical rice-size droppings in some kitchen drawers, a common mouse hot spot, Herbert said. As they pulled out the dishwasher, they discovered the insulation saturated with droppings. Ten mouse traps made no dent in the onslaught. When the homeowners watched a mouse sitting next to a trap, munching on a piece of cheese, Herbert received a call.

Another homeowner with an in-ground pool who would trap a mouse or two in the pipes every week was pulling out 30 mice every seven days this season.

“It gives you an idea about the increase in population,” said Herbert, who treated the home with bait stations, a plastic device with poison inside. The mice eat the poison and die in their nests within three to five days.

Herbert said people shouldn’t wait too long to take action after they see droppings.

“I’ve been to homes where people have just let it go,” he said, adding that evidence of mouse droppings also signals the presence of urine.

Herbert comes armed with unpleasant figures. If a pregnant mouse gets into a home, it can have a litter of five to seven pups every 30 days. Those pups, in turn, can reproduce in 45 days. In one night, a single mouse will leave, on average, 65 droppings, between 1,000 and 3,000 micro-droplets of urine and 100 hairs. It can jump 13 inches from the floor onto a flat surface and run vertically on a rough surface.

With the presence of mice comes the risk of exposure to a host of diseases such as meningitis and salmonella. Even after the droppings have been cleaned up, the salmonella virus may stay active in mouse urine for up to 90 days, Haddad said.

Deer mice, which are rare in urban settings, may transmit the hantavirus, a potentially deadly disease with symptoms that resemble influenza, according to the Centers for Disease Control and Prevention. Ticks also feed off mice all year, potentially bringing Lyme disease into homes in the winter, Herbert said.

No one can quite explain the proliferation of mice over the past few years, Herbert said. Haddad cited the unseasonably mild winter as a potential explanation for this season’s sudden rise, a possible decline in predators or a reluctance to deal with the problem before it gets out of hand.

“People pay thousands of dollars to get rid of bedbugs but don’t want to pay any money to get rid of mice,” Haddad said.

Taking a few precautions may keep the unwelcome visitors at bay. In the High Street home, Herbert found a couple of holes in the basement walls that gave the mice easy access. A mouse only needs a space the size of a nickel to squeeze through, he said. They may also enter via water spigots, gas meters or utility cables.

As common as mice may be, especially in antique homes, there is still stigma associated with having a mouse problem, Herbert said. Although they do not discriminate between clean and less immaculate homes, he said they are more likely to thrive in a messy environment, which offers more places to nest and an ample supply of food.

A mouse in a drain pipe under the back deck of a local residence.
Simple measures such as storing grains in steel containers, keeping bird feeders away from the house and using garbage cans with tight-fitting lids can make a difference, he said.

For more information on rodent-proofing, the Newburyport Health Department offers guidance and an educational brochure, according to Public Health director Robert Bracey.