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RODENTS

House Mouse

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Description & Behavior:

The House Mouse (Mus domesticus/musculus) is the most common rodent to invade homes in large cities such as Toronto, and the Greater Toronto Area.  An adult mouse is 3 – 4 inches in length, not including the tail, which is about the same length as the body.  Mice have short hair that is light brown or gray to black in color, and have a long, almost hairless tail.   They feed on grains, fruits and vegetables, stored food and refuse and live an average of one year.

 

Mice have poor sight, particularly during the day.  They depend on their highly developed hearing and sense of smell to get around and communicate with other mice.   Although primarily nocturnal, large population density, and scarcity of food will bring them out during the day.

 

Mice are found in and around homes and commercial structures, as well as in open fields and agricultural areas.  They are known to invade homes in search of food and shelter.  Although mice are year round pests, they are more commonly encountered indoors in fall and winter as temperatures drop and food becomes scarce.

 

Mice enter homes/structures through small holes and cracks. They can squeeze through openings that are no larger than the size a dime. Once inside, mice nest in your wall voids (between the drywall and brick), in between floorboards, and garage.  Since they are such terrific climbers, they can be found nesting in your attic as well.        

 

Mice multiply very quickly. A female mouse reaches sexual maturity at 35 days, and can have 5 to 10 litters per year.  Each of these litters contains between 4 - 8 offspring.  Since the newly born female offspring will be able to reproduce after only one month, within less than three months 5 mice can multiply into 50.  For this reason it is crucial to deal with a mouse infestation as soon as any evidence is found.

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Dangers & Damage:

Mice can also be very destructive.   Like most rodents, they have an upper and lower pair of constantly growing incisor teeth that are kept razor sharp.  These teeth are strong enough to gnaw through iron and several other metals.  They use their teeth to chew holes in drywall, shred fabric and other items for nesting purposes, cause damage to wooden beams, and most threatening, chew the insolation around electrical wires which can cause fires.

Mice carry and transmit various diseases, bacteria, viruses and parasites through their droppings, urine, saliva, and even their nesting materials.  Most nests contain fleas and ticks, which can also transmit other illnesses.  Disease spreads by having direct contact with or breathing in dust that has been contaminated by rodent urine or droppings.  Since mice urinate in micro droplets as they forage and travel about, a surface contaminated with their saliva or urine is almost impossible to detect.  For this reason, if you encounter any evidence of mice, dispose of boxed or bagged food items that may have been compromised, and store newly bought items in sealed containers i.e. plastic containers with lids.

 

The most common disease carried by the House Mouse is LCMV (Lymphocytic choriomeningitis virus).  Although less likely to effect those with normal immune systems, it can cause serious infections in those with weakened immune systems like children and the elderly.

 

For more information on rodent-related diseases, visit http://www.cdc.gov/rodents/diseases/direct.html

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Mice can also be very destructive.   Like most rodents, they have an upper and lower pair of constantly growing incisor teeth that are kept razor sharp.  These teeth are strong enough to gnaw through iron and several other metals.  They use their teeth to chew holes in drywall, shred fabric and other items for nesting purposes, cause damage to wooden beams, and most threatening, chew the insolation around electrical wires which can cause fires.

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How Do I Know If I Have A Nest In My Home?

The first sign of mice is usually seeing their droppings, which are approximately the size and shape of an uncooked grain of rice.  These droppings may be found in your garage, furnace room, and of course, under your kitchen sink.  Mice can also sometimes be heard scurrying above your head in your basement or bedroom while you are trying to sleep, and occasionally you can even hear their high-pitched squeaks resonating from behind your walls.  Finding little bits of food or chewed up packages as well as actually seeing them dash across a room is an obvious sign of a nest in your home.

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Prevention:

  • Clear debris such as tree/grass-clippings, firewood etc. around the perimeter of your home to reduce exterior nesting areas close to the home.

  • Caulk around all hoses/pipes leading inside the home such as gas pipes, furnace pipes, AC hose lines etc. using steel wool and spray foam.

  • Clean barbecues of food particles after each use.

  • Store grass and birdseed in sealed containers, particularly if stored in sheds or garage.

  • Keep areas such as basement and garage free of clutter. A cluttered, undisturbed environment provides an ideal nesting location.

  • Store pet food in rodent-proof containers.

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shutterstock house mouse.jpg

Deer Mouse

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Description & Behavior:

The Deer mouse (Peromyscus maniculatus) is pale gray to reddish brown in color, and has white fur on its belly, feet and underside of tail.  It is about 3 – 4 inches in length, from tip of snout to base of tail; the tail being approximately the size as its body.  Although sometimes similar in size to a House mouse, an adult Deer mouse can weight up to 50% more. Additionally, the Deer mouse has larger eyes and ears than that of the House mouse, and is also hairier.  The Deer mouse is also more likely to be found in higher elevations i.e. attics.  Their diets are similar to that of a House mouse, and live for approximately the same amount of time, one year.

 

Although distantly related to the House mouse, the Deer mouse has similar characteristics, poses similar health threats, and lives in identical environments.

For more information on the dangers and damage Deer mice can cause, identifying infestations, as well as preventative measures one can take, please refer to the above information under House mouse. 

 

The primary disease linked to Deer mice is Hantavirus pulmonary syndrome (HPS) due to a major outbreak occurring in the US in 1993.  Since then, there have been some cases reported throughout North and South America with thirty-eight percent of them been fatal.

 

For more information on Hantavirus visit;

http://www.cdc.gov/rodents/diseases/direct.html

shutterstock deer mouse.jpg

Brown Rat or Norway Rat

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Description & Behavior:

The Brown rat, also know as the Norway rat (Rattus norvegicus) measures about 16 inches from the tip of its nose to the end of its tail.  The length of the tail is slightly shorter than the body.  It is typically grayish brown in color, but can be pure gray or reddish brown.  The Norway rats’ head is relatively larger than its body while its ears are smaller relative to the head.  Norway rats have short coarse hair covering their body, but their ears and tail are bald.   Adult rats weight about 400g-500g males being larger than females.  Norway rats are excellent swimmers, which is why they are sometimes referred to as water rats.  They feed on grains, fruits and vegetables, stored food, refuse and other small animals.  They only live for six months in the wild, but under favorable conditions can live up to two years.

 

Norway rats are extremely intelligent and tremendously adaptable.  They have poor eyesight and are typically active at night.  For this reason, they depend on their highly developed hearing and sense of smell to get around and communicate with other rats.  They are able to feel their way in total darkness only using their paws and whiskers.  Norway rats are able to follow elaborate pathways to get to areas rich in food resources.   Scent is the Norway rats most heightened attribute.  This allows them to distinguish between other rat packs, and quickly detect danger and avoid new objects and foods.  Therefore, they will often stay away from traps and baits for several days or weeks following their initial placement.

 

Although originated in northern China, it is believed that Norway rats got to North America as ship stowaways.  By the 18th Century they were found on every continent except Antarctica.    Norway rats typically lived in forests and brushy areas, but today they are primarily found in urban neighborhoods living alongside humans.  They live in sewers, basements, old buildings, dumps, fields, gardens ponds, and farms, generally near a water source.  They create complex burrow systems but will also take advantage of man made tunnels such as sewers.

 

Rats enter homes/structures through small holes.  They can squeeze through openings that are no larger than the size of a quarter.  Although they tend to be outdoor animals that will infest areas around structures, rather than the structures themselves, nesting in close proximity allows them to gain entry using holes and cracks in the foundation. (See images) Rats have also been known to access structures by gnawing, jumping, or swimming through sewers and entering through toilets or broken drains.  Since they prefer dark moist areas, once inside, rats tend to dwell in basements and ground floor.

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Norway rats multiply very quickly.  A female rat reaches sexual maturity at five weeks.  Following a 22-24 day Gestation period, she will give birth to an average of 8-14 pups.  Approximately 18 hours after giving birth, female rats are able to mate again.  This reproductive ability is responsible for their huge birthrates.  One female rat can give birth to 60 pups in one year.

 

Despite the fact that rats have many natural predators, and humans spend a great deal of effort trying to eradicate them, it is estimated that rats cause over 1 billion dollars in damage in the US each year, and their numbers are increasing nationwide.

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Dangers & Damage:

Rats harbor and transmit numerous diseases, bacteria, viruses and parasites through their droppings, urine, saliva, and even their nesting materials.  Most nests contain fleas and ticks, which can also transmit other illnesses.  Disease spreads by having direct contact with or breathing in dust that has been contaminated by rodent urine or droppings as well as eating soiled food items.  For this reason, if you encounter any evidence of rodents, dispose of boxed or bagged food items that may have been compromised, and store newly bought items in sealed containers i.e. plastic containers with lids.

 

Rats have been known to carry and transmit bubonic plague, typhus, trichinosus, tularemia, infectious jaundice and more.  It is believed that rat-borne diseases have killed more people in the last 1000 years than all of the wars ever fought.

 

For more information on rodent-related diseases, visit; http://www.cdc.gov/rodents/diseases/direct.html

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Rats are also extremely destructive.  Rats have an upper and lower pair of constantly growing incisor teeth that are kept razor sharp.  These teeth have been tested to be harder than iron and several other metals.  For this reason, Rats can gnaw on most building woods, aluminum sheathing, rock, cement, asphalt, and softer metals such as lead and copper.  They have been known to disassemble buildings by gnawing on the structural support timbers.   Rats, like other rodents, are of particular concern due to their attraction to wires.  They can cause serious structural damage as well as short circuit fires as they spend 2% of their day gnawing on various objects.

 

Pharaoh ants are a resilient species that are extremely difficult to completely eliminate.  It is therefore advisable to employ the services of a pest control company like Delta Pest Control as soon as any activity is found.

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How Do I Know If I Have Rats In My Home?

The first signs of rats is usually seeing their droppings, which are approximately 3-4 times the size and shape of an uncooked grain of rice.  These droppings may be found in your garage, furnace room, under your kitchen sink, but more likely in basements where conditions are ideal.  You may also find that the soil of your potted houseplants has been disturbed.  Occasionally you might even be able to hear their squeaks and chirps resonating from behind your walls.

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Prevention:

  • Rat-proof home or structure by sealing any holes and crackswith spray foam and steel wool.

  • Do not leave food for stray cats or other animals outdoors.

  • Seal openings in building foundations (point of vulnerability)

  • Store bird /grass seed in sturdy containers.

  • Do not maintain a birdfeeder near the house.

  • Store pet food in rodent-proof containers.

  • Clear debris and cut hedges back around the perimeter of your home.

shutterstock norway rat.jpg

Black Rat or Roof Rat

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Description & Behavior:

Black rat or Roof rat (Rattus rattus) is typically black in color, but may also be brown-backed with a lighter belly.  Although not as common as the Norway rat here in Toronto, as it prefers warmer climates, it has learned to adapt to our colder weather.  The roof rat is about the same size as the Norway rat (16 inches), but its tail is longer than its body.  This is one of its key identifying characteristics.  The Roof rat weights about 150g-300g, and is more sleek and agile than the Norway rat.  The roof rat will use electrical lines, tree branches and vines to gain aerial access into structures.  For this reason they are more commonly found in higher elevations, such as attic spaces, trees, and overgrown shrubbery.  Roof rats eat a wide variety of foods, but prefer fruits, nuts, berries, slugs and snails.  They only live for about one year in the wild, but under favorable conditions can live up to four years.

 

Like Norway rats, Roof rats are extremely intelligent and tremendously adaptable.  They have poor eyesight and are typically active at night.  They depend on their highly developed hearing and sense of smell to get around and communicate with other rats.  They are able to feel their way in total darkness only using their paws and whiskers.  Roof rats routinely travel up to 300 feet for food.  They can live in one area but feed in another.  They can be seen at night running along overhead utility lines and fence tops using their long tail for balance.  They can swing beneath rafters and climb pipes and wires, and jump as far as 4 feet from branches to roof tops.  Since they are such agile climbers they are able to quickly escape predators.

The average number of litters a female roof rat has per year depends on many factors, but generally roof rats have 3 to 5 litters with 5 to 8 young in each litter.  Although they breed less often than the Norway rat, one female can give birth to up to 40 pups per year.

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Dangers & Damage:

Rats harbor and transmit numerous diseases, bacteria, viruses and parasites through their droppings, urine, saliva, and even their nesting materials.  Most nests contain fleas and ticks, which can also transmit other illnesses.  Disease spreads by having direct contact with or breathing in dust that has been contaminated by rodent urine or droppings as well as eating soiled food items. 

For this reason, if you encounter any evidence of rodents, dispose of boxed or bagged food items that may have been compromised, and store newly bought items in sealed containers i.e. plastic containers with lids.

 

Rats have been known to carry and transmit bubonic plague, typhus, trichinosus, tularemia, infectious jaundice and more.  For more information on rodent-related diseases, visit; http://www.cdc.gov/rodents/diseases/direct.html

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Rats are also extremely destructive.  Rats have an upper and lower pair of constantly growing incisor teeth that are kept razor sharp.  These teeth have been tested to be harder than iron and several other metals.  For this reason, Rats can gnaw on most building woods, aluminum sheathing, rock, cement, asphalt, and softer metals such as lead and copper.  They have been known to disassemble buildings by gnawing on the structural support timbers.   Rats, like other rodents, are of particular concern due to their attraction to wires.  They can cause serious structural damage as well as short circuit fires as they spend 2% of their day gnawing on various objects.

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Prevention:

  • Rat-proof home or structure by sealing any holes and cracks.

  • Do not leave food for stray cats or other animals outdoors.

  • Seal high openings in buildings (point of vulnerability)

  • Trim ivy growing on structure walls.

  • Store bird /grass seed in sturdy containers.

  • Do not maintain a birdfeeder near the house.

  • Store pet food in rodent-proof containers.

shutterstock roof rat.jpg

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