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Know your enemy.

Here is a little bit of information about the behaviour and breeding habits of the more common pests that we encounter in Ontario. Click the orange button to see the service we provide for each pest.

House Mouse 

mus musculus

Most homes have, have had, or will have mice at some point. 

 Mice are a very common pest. In most homes the population is limited to the attic and crawl space. If a population becomes well established you may begin to notice evidence of their activity. Signs of mice can be very subtle like scratching or chewing sounds in the walls or ceiling. Droppings in the home and food items with gnaw marks are much harder to ignore. 

 The gestation period for a female mouse is about 19–21 days, and they give birth to a litter of 3–14 young (average six to eight). One female can have 5 to 10 litters per year, so the mouse population can increase very quickly. Breeding occurs throughout the year.

 The pups are weaned at around 21 days. Females reach sexual maturity at about six weeks of age and males at about eight weeks. 

 House mice usually live in proximity to humans, in or around houses or fields. Originally native to Asia (probably northern India), they spread to the Mediterranean Basin about 8000 BC, only spreading into the rest of Europe around 1000 BC. This time lag is thought to be because the mice require agrarian human settlements above a certain size. They have since been spread to all parts of the globe by humans.

Raccoon procyon lotor

York Region is home to thousands of raccoons. They can cause damage to your home or just be a nuissance. 

 Raccoons are one part teddy bear, one part master thief, and one part chain saw. Their intelligence and playful nature makes them a lot of fun to watch. Unfortunately they are making their homes in our attics, garages and sheds and they can be quite messy and destructive. Though rabies is extremely uncommon, raccoons and their feces can potentially carry parasites that can be harmful to humans and pets. 

 Raccoons usually mate in a period triggered by increasing daylight between late January and mid-March. If a female does not become pregnant or if she loses her kits early, she will sometimes become fertile again 80 to 140 days later. After usually 63 to 65 days of gestation, a litter of typically two to five young is born. Males have no part in raising young. Once the kits weigh about 1 kg, they begin to explore outside the den, consuming solid food for the first time after six to nine weeks. In the fall, after their mother has shown them dens and feeding grounds, the juvenile group splits up.While many females will stay close to the home range of their mother, males can sometimes move more than 20 km away. This is considered an instinctive behavior, preventing inbreeding. However, mother and offspring may share a den during the first winter in cold areas.


American red squirrel Tamiasciurus hudsonicus

Eastern gray squirrel Sciurus carolinensis

  Red squirrels and eastern grey squirrels (eastern gray squirrels can also have black fur) are frequent visitors to our backyards and bird feeders. Outside they do no harm, inside the attic is a different story. They squeeze in through soffits or chew through roof vents. They can cause roof leaks and pile your attic full of pine cones and debris. Not to mention the constant pitter-patter of squirrel feet on your ceiling and soffit. 

 Eastern gray squirrels can breed twice a year, but younger and less experienced mothers will normally have a single litter per year in the spring. Depending on forage availability, older and more experienced females may breed again in summer.  The first litter is born in February or March, the second in June or July. Normally, one to four young are born in each litter, but the largest possible litter size is eight. The gestation period is about 44 days. The young are weaned at around 10 weeks, though some may wean up to six weeks later in the wild. They begin to leave the nest after 12 weeks. Male Eastern grays are sexually mature between one and two years of age. Females are not normally fertile before at least one year of age.

 American red squirrel females enter estrus for only one day, but venture from their territory prior to ovulation, and these exploratory forays may serve to advertise their upcoming estrus. Females will mate with 4 to 16 males. Gestation has been reported to range from 31 to 35 days. Females can breed for the first time at one year of age, but some females delay breeding until two years of age or older. Most females produce one litter per year, but in some years reproduction is skipped, while in other years some females breed twice. Litter sizes typically range from one to five, but most litters contain three or four offspring. Offspring grow at approximately 2g/day while nursing, and reach adult body size at 125 days. They first emerge from their natal nests at around 42 days, but continue to nurse until approximately 70 days.

Common Starling

Sturnus vulgaris

After two failed attempts, about 60 Common starlings were released in 1890 into New York's Central Park by Eugene Schieffelin.The original 60 birds have since swelled in number to 150 million, occupying an area extending from southern Canada and Alaska to Central America.


 Common starlings are very intelligent and social birds. They love subdivisions and new homes because of an abundance of wall vents and other gaps and cracks. They will pack a wall vent full of nesting materials and lay their eggs inside. Starlings (and many other birds) are lovely from far away, but up close is a different story. They are host to parasites and creepy crawlies. The combination of decaying organic matter, feces, maybe an egg shell or two can cause quite an offensive odour and that's if all is well for the nest. When a nest dies either with eggs or hatchlings the odour can be pretty bad once it starts to decompose. 

 Breeding takes place during the spring and summer. Incubation lasts thirteen to fourteen days. Both parents share the responsibility of brooding the eggs, but the female spends more time incubating them than the male, and is the only parent to do so at night when the male returns to the communal roost. 

The young are born blind and naked. They develop light fluffy down within seven days of hatching and can see within nine days. Once the chicks are able to regulate their body temperature, about six days after hatching, the adults largely cease removing droppings from the nest. Nestlings remain in the nest for three weeks, where they are fed continuously by both parents. Fledglings continue to be fed by their parents for another one or two weeks. A pair can raise up to three broods per year, frequently reusing and relining the same nest, although two broods is typical. Within two months, most juveniles will have moulted and gained their first basic plumage.



Striped skunk

mephitis mephitis

Skunks are very shy and sensitive animals. They prefer privacy and if they are disturbed they will let you know. 

 Skunks are one of the most famous animals in North America and for good reason. They have well-developed anal scent glands that can emit a highly unpleasant odour when the skunk feels threatened. They enjoy living under sheds and decks but generally avoid people. Although they have a tendency to get themselves trapped in garages from time to time. 

 Skunk spray contains chains of carbon and hydrogen with the sulfur and hydrogen thiol group attached to one end. They're volatile, which means they disperse easily in the air, and they're easily picked up by the human nose. The spray also consists of thioacetates, other groupings of carbon and hydrogen that are, at first, not particularly smelly. When water hits them, it rearranges them into more potent configurations. A dog or human that's been sprayed by a skunk will sometimes get smellier after being bathed in water. Many products are available to help remove the odour of skunk spray. Pest Hound recommends Head and Shoulders original scent (oh ya, believe it) and many showers for humans. Also, you will likely have to throw out any clothing that contacted the spray. For pets, speak to your vet. 

The striped skunk does not hibernate but instead goes into a dormant or semi-active state. Outside the breeding season, males are solitary and try to build fat reserves while females defend their maternity dens.

Breeding mostly occurs from mid-February to mid-April. A skunk breeds only once a year. The young are born in May or early June. Skunks tend to have litters of 4 to 8. The young are born hairless but have their striping pattern. By eight days, the young’s musk odour can be emitted. By 22 days, the young’s eyes open. After an eight week nursing, the litter then hunt with their mothers and eventually they disperse. Skunks are crepuscular. Beginning their search for food at dawn and dusk, they feed on mice, eggs, carrion, insects, grubs, and berries. And garbage of course. 

Wasps and hornets

There are several types of wasps and hornets in canada. Three common pest species are mentioned here. 

Wasps and hornets are a constant irritation during the warmer months. They are usually harmless but when provoked, they can deliver a painful sting. For people with allergies or sensitivities to their venom, stings can be very dangerous. To most people, however, they are just unpleasant and cause localized swelling and discomfort. Wasps and hornets have a smooth stinger, capable of stinging multiple times. Honey bees on the other hand have a barbed stinger that attaches to the skin of the stingee. This yanks out their stinger along with the venom gland which continues to pump, killing the bee. There is so much information and so many different species that it is difficult to sum up. The three main pest species in Ontario that we encounter are:

yellow jackets, bald-faced hornets, and paper wasps.

Yellow Jackets vespula maculifrons and others can be identified by their distinctive markings, their occurrence only in colonies, and a characteristic, rapid, side to side flight pattern prior to landing. All females are capable of stinging. Yellow jacket nests usually last for only one season, dying off in winter. The nest is started by a single queen, called the "foundress". Typically, a nest can reach the size of a basketball by the end of a season. The nest can be either exposed like in the picture to the right, or contained within a recess like a wall or soffit. 

Bald-faced hornets dolichovespula maculata have striking black and white colouration but their habits are very similar to their cousins mentioned above. They are noticeably larger than yellow jackets and every bit as aggressive. Bald-faced hornets typically nest in large trees or bushes but can be found attached to the wall of your house or underside of the soffit. 

Paper wasps (the name "paper wasps" typically refers to members of the vespid subfamily polistinae) are 1.8 to 2.5 cm long wasps that tend to be more docile than other species. That said, be warned, they absolutely do sting. Paper wasps are also sometimes called umbrella wasps, due to the design of their nests. The nests are usually placed high on your house in a sunny spot but under shelter. Unlike the closed football shaped nests of yellow jackets and bald-faced hornets, paper wasps build nests that are exposed and resemble a sunflower without petals. They can be seen crawling over the surface of active nests. 



There are many types of ants in canada. Identifying them can be tricky and is essential to treating them properly. 

 There is a big difference between carpenter ants such as camponotus pennsylvanicus and pavement ants tetramorium caespitum. Their nesting, feeding and impact on our homes can differ greatly.

 Carpenter ants are quite large and can infest rotten or decaying wood, adding to structural issues and causing significant damage. Pavement ants are smaller, prefer to nest in sand and loose soil. They are a nuissance but frankly do not cause very much harm. There are other ants such as Pharaoh ants monomorium pharaonis that can be very difficult to treat and will often pop up from place to place while a treatment is in process.

 If you have an ant issue in or around your home, please take note of where and when you are seeing them and acquire a sample for identification. We can either identify your sample on site or you can send us a picture (clear, with good resolution) via email for an i.d.

Little brown Bat

myotis lucifugus


The little brown bat is the most common and widely distributed of Canada's bat species. The bats' diet makes this species beneficial to agriculture as it eats many species of agricultural pests.

 There are eighteen indigenous species of bats in Canada, which are found in many parts of the country. They are exclusively insectivores and are important members of the food chain controlling pest species like mosquitoes, moths and many other insects. A single little brown bat can eat 500 to 1000 mosquitoes in a single hour. As with most bats, the little brown bat is mostly active at night.

 Most temperate bats either migrate or hibernate, but little brown bats do both. In summer, the males and females live apart, the females raise the young. Little brown bats undergo a prolonged period of hibernation during the winter due to the lack of food. They hibernate in caves as a community.

 When they emerge in the spring, the females go to nursery colonies which may often be the same place where they were born. These nursery colonies consist mainly of adult females and their young and can be located in the attics of warm buildings where there is high humidity. These colonies sometimes reach numbers of well over 1000 individuals. Gestation lasts 50–60 days. 

The young are born with their eyes closed and will hang in the nursery while their mothers forage at night. Their eyes open on their second day. They nurse constantly until they are two weeks old. At three weeks, they learn to fly. By four weeks, they are adult sized. Females may be sexually mature in the fall after their birth, but males may take a year longer. About half of females and most males breed during their first autumn.

Pest Hound Inc. DOES NOT treat Honey bees with pesticides. Wasps are predators and while they are an important part of the food chain, they are not essential to agriculture like honey bees. If you have a Honey bee swarm or hive on your property Pest Hound will happily recommend the services of apiarist, who will remove the swarm without harming them. 

This information above is designed as a guide to help you undertand your pest a little better. If you have any questions that were not answered or are dealing with an animal that is not on this list please call us

289-221-5811 or email and we will provide you with as much info as possible. 

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