Rodent Pest Control

Black rats are long and thin rodents that have large eyes and ears, a pointed nose and a scaly tail. They have soft and smooth fur that is brown with intermixed spots of black. Their undersides are often white, gray or black.

The life cycle of a black rat can be from a year to 18 months. During this period, the female can typically breed 6 times with an average litter of 6-8.

Black rats are omnivores and eat a wide range of foods, including seeds, fruit, stems, leaves, fungi, and a variety of invertebrates and vertebrates.

Black rats tend to live in polygynous groups with multiple males and females. These animals strip bark off of trees, contaminate human food sources, and are overall pests.

Black Rats are born in a nest in a litter of 6-8 young. The nest is often in a secure place with nesting debris such as in an attic in the insulation. They are born tiny and hairless (pinkies), with eyes sealed shut.

Black rats can carry a number of pathogens, of which bubonic plague , typhus, Weil’s disease, toxoplasmosis and trichinosis are the best known.

Medieval Pope Gregory IX considered cats to be the ‘incarnation of Satan’. Leading to a mass killing of cats, causing the rat population to swell, quickening the spread of the Black Death.

Brown or dark grey color, and the underside a lighter brown to light grey.

The head and body length ranges from 15 to 28 cm while the tail ranges in length from 10.5 to 24 cm, therefore being shorter than the head and body.

Adult weight ranges from 140 – 500g. Exceptionally large individuals can reportedly reach 900 -1,000g but are not expected outside of domestic specimens. Reports of rats attaining sizes as big as cats are exaggerations, or misidentifications of larger rodents, such as the coypu and muskrat. In fact, it is common for breeding wild brown rats to weigh (sometimes considerably) less than 300g.

The gestation period is 21 days, and litters can number up to 14. They reach sexual maturity in about five weeks and the maximum life span is three years.

They will eat any food that is left unprotected. Brown Rats have also been known to eat grain or kill insects, water creatures such as snails, fish and mussels, small birds and reptiles for food.

Brown rats are capable of producing ultrasonic vocalizations. As pups, young rats use different types of ultrasonic cries to elicit and direct maternal behavior.  Although pups will produce ultrasounds around any other rats at 7 days old, by 14 days old they significantly reduce ultrasound production around male rats as a defensive response. Adult rats will emit ultrasonic vocalizations in response to predators or perceived danger. The frequency and duration of such cries depends on the sex and reproductive status of the rat. The female rat will also emit ultrasonic vocalizations during mating.

Brown rats also produce communicative noises capable of being heard by humans. The most commonly heard in domestic rats is bruxing, or teeth-grinding, which is most usually triggered by happiness, but can also be ‘self-comforting’ in stressful situations, such as a visit to the vet. The noise is best described as either a quick clicking or ‘burring’ sound, varying from animal to animal.

In addition, they commonly squeak along a range of tones from high, abrupt pain squeaks to soft, persistent ‘singing’ sounds during confrontations.

Rats are territorial animals, meaning that they usually act aggressively or scared of strange rats. Rats will fluff up their hair, hiss, squeal, and move their tails around when defending their territory. Rats will chase each other, groom each other, sleep in group nests, wrestle with each other, have dominance squabbles, communicate, and play in various other ways with each other. Huddling is an additional important part of rat socialization. Huddling is often supposed to have a heat-conserving function. Nestling rats especially depend on heat from their mother, since they cannot regulate their own temperature.

Brown rats in particular will dig rat holes in areas of a garden to create rat burrows where they will nest, store food and raise young rats.

Brown Rats carry diseases which can be easily spread to humans, rats transfer diseases like Leptospirosis or Weil’s disease, Salmonella, Listeria, Toxoplasma gondii and Hantavirus. Brown Rats can also inflict a great amount of structural damage.

Rats succumb to peer-pressure, just like humans. Brown rats are prone to disregard personal experiences in order to copy the behaviour of their peers. The urge to conform is so strong that they will even choose to eat unpalatable food if they are in the company of other rats who are eating it.

The only brown rat-free areas in the world are the continent of Antarctica, the Arctic, some isolated islands, the Canadian province of Alberta, and certain conservation areas in New Zealand.

House mice have an adult body length (nose to base of tail) of 7.5–10 cm and a tail length of 5–10 cm. The weight is typically 40–45 g. In the wild they vary in color from grey and light brown to black. They have short hair and some, but not all, sub-species have a light belly. The ears and tail have little hair.

House mice usually live less than one year in the wild, due to a high level of predation and exposure to harsh environments. In protected environments, however, they often live two to three years.

A mouse eats seeds, cereal grains, or sweets but will eat almost anything. Mice do not need much water; they get most of their water requirements from their food

The social behavior of the house mouse is not rigidly fixed into species-specific patterns but is instead adaptable to the environmental conditions, such as the availability of food and space. This adaptability allows house mice to inhabit diverse areas ranging from sandy dunes to apartment buildings.

House mice have two forms of social behaviour:

1. House mice in buildings and other urbanized areas with close proximity to humans are known as commensal. Commensal mice populations often have an excessive food source resulting in high population densities and small home ranges. This causes a switch from territorial behaviour to a hierarchy of individuals.  The social unit of commensal house mouse populations generally consists of one male and two or more females, usually related. These groups breed cooperatively, with the females communally nursing.
2. In open areas such as shrubs and fields, the house mouse population is known as noncommensal. These populations are often limited by water or food supply and have large territories. Aggression is higher in noncommensal populations.

Both commensal and noncommensal house mouse males aggressively defend their territory and act to exclude all intruders. Males mark their territory by scent marking with urine. In marked territories, intruders showed significantly lower aggression than the territory residents. House mice show a male-biased dispersal; males generally leave their birth sites and migrate to form new territories whereas females generally stay and are opportunistic breeders rather than seasonal.

The mouse nest is made usually of scrap materials, gathered after a lot of chewing on various fabric the nest provides shelter and security for female mice to give birth to the new litter.

While the common house mouse is not as dangerous to your health they can still spread disease, such as hantavirus, salmonellosis and listeria through their urine, droppings, saliva and nesting materials.