Newest articles on The Sacramento Press tagged as "norway rat"

Rats grow fat and happy, thanks to mild Sacramento winters

2010-01-27T06:23:27Z

Calls have been pouring into our Sacramento pest control office, with homeowners and business owners reporting that, suddenly, rats have moved into their attics and garages.

Now rat problems always grow worse during our chilly, rainy Sacramento winters, because, like us, the rats are looking for a cozy, dry place indoors where they can build nests and have babies... lots and lots of babies—three to five litters per year, and as many as eight rat pups per litter!

But this year we’re seeing something a little different: The rats our expert pest control technicians are pulling out of the traps they place are huge... some of them nearly a foot-and-a-half long, measuring both body and tail.

What could be creating this bumper crop of plus-size rats? People pouring multi-vitamins down the kitchen sink? Radiation from so many people constantly using their cell phones?

No, far from being a plot line from an upcoming sci-fi movie, the fat and happy rats we’re seeing are simply the products of a series of fairly mild winters in the Sacramento region. Whereas in a normal winter, a large proportion of rats naturally succumb to cold, exposure and scarcity of food, in a mild winter, more rats live to see the spring. A rat whose normal life span might be two years may live to be three, growing correspondingly larger with age. Foods that rats like, such as seeds and grains, are more abundant during mild years, so the surviving rats get plenty to eat.

There are numerous examples of mild winters leading to a boom in rat populations. In 2002, the city of Boston was overrun with rats; thanks to a series of mild New England winters, instead of some 30 percent of rats dying off in frigid cold, only about 5 percent succumbed, according to the Boston Phoenix newspaper (http://www.bostonphoenix.com/boston/news_features/top/features/documents/02194425.htm).

A 2009 article in the UK Guardian newspaper reports the worst rat infestation in 30 years, due to a run of mild winters, and warns consumers that the overpopulation of rats, combined with a bumper wheat crop could increase the danger of rodent droppings in whole-grain breads. Foods made with whole grain flour were more susceptible to rat droppings, the article stated, because they are less processed than goods made with white flour.

Perhaps the most amusing—if alarming—example of rats gone wild was the 2002 Los Angeles Times article reporting that rats seemed drawn to the lifestyles of the rich and famous. One well-to-do Beverly Hills doctor and his party guests were horrified to discover three rats helping themselves to his outdoor buffet. Just a few days later, on a warm Saturday afternoon, the physician found five rats swimming in his marble pool. The culprit: several mild Southern California winters in a row, coupled with near-drought conditions (similar to recent climate conditions in our Sacramento region) that drove the rats from fields and vacant lots into the lush, well-watered gardens and patios of upscale L.A. (http://www.nytimes.com/2002/09/17/us/up-down-in-and-out-in-beverly-hills-rats.html?pagewanted=1)

While such tales may make us laugh, the fact is that rats pose a danger to our homes, families and businesses and to the public health. In addition to carrying diseases and contaminating foodstuffs, rats pose a fire hazard due to their constant gnawing.

Because their four long incisor teeth grow very rapidly and continually throughout the rats’ lifespan, they must constantly gnaw to keep the teeth worn down (http://www.ratbehavior.org/Teeth.htm). If they were to stop, their long, sharp front teeth would grow in spirals and impale them. Among rats’ favorite teething toys appear to be electrical wires, telephone wires, satellite and cable TV wiring and alarm-system wires—at best a nuisance or a repair bill, at worst a fire that destroys a home or place of business.

Rat infestations are a stubborn pest control problem best left to licensed and trained pest control professionals. To learn more about rats and other rodents and how to prevent infestations, read our earlier blog post at http://earthguardpest.com/blog/?p=21 or visit www.earthguardpest.com.

Tiny mice create big problems when winter weather drives them indoors

2009-11-29T02:29:46Z

They may be smaller and, some say, cuter, but in terms of pest control, mice are a more prevalent, more damaging and tougher problem than their two rodent cousins, rattus rattus (roof rats) and Rattus norvegicus (Norway rats). And as our Northern California winter grows colder and wetter, mice are more likely to set up housekeeping in our cozy homes and businesses.

The mice we see most often in our Sacramento pest control business are the house mouse (Mus musculus). Two other types of mouse, the deer mouse and the white-footed mouse, also may invade human dwellings but are most often found in cabins and homes in remote or rural areas.

The house mouse can be easily distinguished from deer and white-footed mice by its uniform gray or light brown coloration and a nearly hairless tail. In comparison, the other two species are darker on top with light-colored bellies and tails that likewise are covered with dark fur on top, lighter fur on bottom. House mice weigh about half an ounce and are 5 to 7 inches in length, including their 3- to 4-inch tails.

One reason mice present such a tough pest control problem is their small size. They need only a quarter-inch gap to gain entry into a building and require only minute amounts of food and water to survive. As a result mouse infestations are much more common and difficult to control than rat infestations—and every bit as hazardous to health and property.
Mice eat and contaminate human and pet foods, preferring grains but apparently willing to nibble on almost anything. One of our Sacramento pest control customers discovered a nest of mice in a trunk where she stored historic family documents, vintage clothing and other mementoes. Not only did she find the remains of precious keepsakes shredded in a pile, she found dry dog food nuggets the mice apparently had confiscated from her pet’s dish and tucked away for safe-keeping.

Mice transmit diseases such as salmonellosis (food poisoning) and can cause significant property damage, chewing through electrical wires, shredding insulation and gnawing woodwork.

Often people discover a mouse problem when they find tiny black droppings or notice the corner of a cracker box or bag of chips has been gnawed away. Mice also have a distinctive musky smell that may be noticeable. They are most active at night, can run straight up vertical walls and jump a foot off the ground. They reproduce rapidly, bearing as many as 10 litters of 5 or 6 pups per year; their life span is approximately one year.

The most effective ways to prevent mice are to keep all foodstuffs tightly sealed in glass or metal containers, to avoid leaving pet food out, keep all trash containers tightly sealed and to seal all gaps and crevices where mice can come in from outside, such as along pipes and wiring conduit. Self-installed metal barriers, such as tin can lids and steel wool, are effective barriers to gnawing but usually don’t provide long-term protection.

Apartment buildings are especially notorious for mouse infestations, in part because mice are able to move easily from apartment to apartment along pipes and conduits and because it is difficult to ensure adherence to pest control measures by all tenants.

Once there is an established infestation in a home or business, it is almost always necessary to use mouse traps or poison bait to eliminate the mice. Baits are dangerous and must be kept inaccessible to children and pets. Electronic devices that emit a high-frequency sound, though widely advertised, are generally ineffective in preventing mice. A good feline or canine “mouser” may help control the mouse population or discourage mice from moving in, but will generally not be able to completely eliminate mice once a site is infested.

To read more about house mice and other rodents and household pests, visit http://www.earthguardpest.com/blog.

Fire and cold weather bring unwanted rat visitors indoors

2009-10-05T20:26:54Z

As the cool weather approaches, so does the likelihood that rodents will be seeking warm nesting sites in the attics, garages and foundations of our homes and commercial buildings. In fact, some of our customers who live near wildfire areas have experienced an unseasonably early influx of these critters, driven from woods and fields by the smoke and flames.

The two most common rodent invaders are mice and rats.

In our region of Central-Northern California, the two most common species of pest rats are the roof rat (Rattus rattus) and the Norway rat (Rattus norvegicus), neither of which are native to California but originated in the Far East and spread across the globe centuries ago. The roof rat is the smaller of the two, averaging 5 to 10 ounces in weight, gray to white in color, with a pointed snout, long ears and a black tail as long as its body. The Norway rat is stockier, weighing 7 to 18 ounces, grayish in color, and with shorter ears and tail than the roof rat.

The roof rat is a good climber, nests in trees and dense shrubs, and may take up housekeeping in your attic, the space above dropped ceilings or even in high cabinets. The Norway rat is a burrower and indoors usually sticks to basements or ground floor spaces. You may spot its nest lined with shredded paper, fabric or other fibrous materials.

Although both these types of rat are common in our region, and highly adapted to residential neighborhoods and urban environs, our Earth Guard customers complain most frequently of the roof rat.

Sometimes depicted as funny and cute in popular media such as the Disney-Pixar movie “Ratatouille,” in fact Rattus rattus and Rattus norvegicus pose serious health and safety problems for home- and business owners. Rats eat and contaminate human and animal food and whatever container or packaging it is stored in; they gnaw on and ruin wooden doors and cabinets, chew through electrical wires and shred insulation to use for their nests. One of our customers recently had to place a service call to her security alarm company when a sensor stopped working; the mystified technician finally found a place in the attic where a rat had chewed through the alarm system wiring.

Rats also carry diseases such as murine typhus, leptospirosis, trichinosis, salmonellosis (food poisoning), ratbite fever and even plague that can be transmitted to humans and other animals.

The first signs of a rat infestation may appear in your yard or garden before the critters have moved indoors. Once they move into your yard, they will eventually move inside, so it’s preferable to catch them early. Common signs of rat activity outdoors include:
• Droppings near pet food containers or dishes or recycling bins;
• Nest materials in wood piles or brush piles;
• Burrows near compost heaps or garbage containers;
• Signs of digging under fences, sheds or doghouses;
• The sight of a rat traveling utility lines or fence tops at dusk;
• Rat carcasses in your outdoor pool or hot tub or dragged to the door by your family dog or cat.

Indoors, you may hear noises coming from your attic, especially at dusk or dawn, or discover a nest inside drawers or behind boxes in your garage, or you may see smudges along walls, pipes or rafters.

Homeowners and business owners can take some common-sense measures to prevent rat infestations, including keeping pet food containers and garbage containers tightly sealed and the areas around them picked up and clean.

Bird feeders also are attractive to rats. Another of our customers, who had multiple bird feeders in her backyard, noticed that the seed-covered bird bell she hung in one corner of her yard would repeatedly disappear almost overnight. She would replace it, and by the next morning, it would be eaten down almost to the plastic hanger. Hungry birds, she thought. The one evening, she happened to be looking out the back door just as dark was settling in and heard a rustling in the leaves above the bird bell. Grabbing a flashlight, she quietly walked over to investigate. The beam of the flashlight revealed an acrobatic roof rat, hanging upside down from the branch, nibbling away.

Storing wood off the ground and eliminating clutter and debris from around building foundations also will discourage rat activity. Roof rats, such as the acrobat caught eating our customer’s bird bell, may use overhanging tree branches, pergolas or dense shrubbery such as star jasmine or ivy as a highway to your roof, where they may find entry to your attic around eaves, pipes or chimney flashing. Trimming trees to leave 2 feet or more between plants and between branches and roof helps discourage these travels. Sealing, screening or plugging openings around wiring conduit or pipes with steel wool or sheet metal, both around your roofline and at foundation level, also are effective at keeping rats out.

Once rats have moved in to your home or place of business, the best way to eliminate them is with the traditional snap traps. A major infestation may require the use of poison bait, which should only be administered by a trained pest control professional. Although customers sometimes request it, the use of live traps is not a good idea. Because the rats are not native to our environment, they cannot be released outdoors, where they pose a danger to humans, pets and property and—because they are an invasive species—to the native ecosystem. In some areas, rats have been known to decimate wild bird populations. Live traps also accumulate bodily waste from the rodents, creating a health hazard for our pest control technicians.

For more information about rats and other environmental and pest control issues affecting Sacramento-area homes and businesses, visit www.earthguardpestcontrol.com/blog. (Norway rat photo credit: National Pest Management Assoc. Inc.)