Bug Category: Rodents

Bat

Summary

There are numerous species of bats found in Virginia, including the Big Brown Bat, the Eastern Red Bat, the Evening Bat and the Gray Bat.

Bats are not only a protected species but they are the most efficient “exterminators” in that they eat many times their own weight in insects in a single season.

Joe Wilson, CEO of PermaTreat Pest Control stated, “When doing bat exclusion work we want to be certain that we do not trap or kill any bats. PermaTreat is in the bat exclusion business exclusively. ”

Step One – Night Inspection

First, inspect at dusk to determine exit/entry points and the size of the infestation. Common exit/entry points include attic louvers, roof lines where sheeting and facia boards meet, under facia boards, and other openings due to deterioration.

Step Two – Day Inspection

Second, inspect during the day to locate exterior structural deficiencies, inside roosting sites (check opposite exit/entry points, wall voids, etc., look for droppings and/or bats), access problems, and to determine equipment needed.

“Bat proofing” is the control method of choice if it is practical and economical. Exclusion is the only method to keep bats out long term. The best time to bat proof is after the bats have left for hibernation in the autumn and before they return in the spring. Summertime bat proofing should only be done after mid-August to avoid trapping young; we never bat proof from early May to mid-August,” confirmed Kevin Walsh, technical advisor for PermaTreat Pest Control.

Ultrasonic devices have not been found to be effective for repelling bats from structures.

On occasion, if 1 or 2 bats enter a structure, open the doors and windows and turn out the lights. The bats will follow the fresh air currents to the outside.

When bat control is done a residual is applied to control the bat ectoparasites, such as mites and bat bugs, which will probably be present. Many of these will bite humans.

Be aware of the potential health hazard that accumulated bat droppings present. These droppings can be left alone if access is secured, or they can be professionally decontaminated and removed.

Black Rat

Summary

Asian black rat, Ship Rat, Roof Rat, House Rat, Alexandrine Rat or Old English Rat is a common long-tailed rodent of the genus Rattus (rats) in the subfamily Murinae (murine rodents). The species originated in tropical Asia and spread through the Near East in Roman times before reaching Europe by the 6th century and spreading with Europeans across the world. Today it is again largely confined to warmer areas, having been supplanted by the Brown Rat (Rattus norvegicus) in cooler regions.

The Roof Rat

Despite its name, it exhibits several color forms. It is usually black to light brown in color with a lighter underside. A typical rat will be 15–20 cm (5.9–7.9 in) long with a further 20 cms (7.9 in) of tail. It is nocturnal and omnivorous, with a preference for grains. Compared to the Brown Rat, it is a poor swimmer, but more agile and a better climber, tending even to flee upwards. In a suitable environment it will breed throughout the year, with a female producing three to six litters of up to ten young. Females may regulate their production of offspring during times when food is scarce, having as few as only one litter a year. R. rattus lives for about 2–3 years. Social groups of up to sixty can be formed.

The Black Rat has been known to fall victim to a number of diseases, of which bubonic plague (via the rat flea), typhus, toxoplasmosis andtrichinosis are the most well known.

In the 1920s in England, several color variations were bred and shown alongside domesticated brown rats. This included an unusual green tinted variety. Today however, very few people keep Black Rats as pets. Most pet rats (or fancy rats) are domesticated brown rats.

In New Zealand, Black Rats have an internationally unusual distribution and importance, in that they are utterly pervasive through native forests, scrublands, and urban parklands. This is typical only of oceanic islands that lack native mammals, especially other rodents. Throughout most of the world, Black Rats are found only in disturbed habitats near people, mainly near the coast. Black Rats are the most frequent predator of small forest birds, seeds, invertebrates, and perhaps lizards in New Zealand forests, and are key ecosystem changers. Controlling their abundance on usefully large areas of the New Zealand mainland is a crucial current challenge for conservation managers.

Brown Rat

Summary

The brown rat, common rat, sewer rat, Hanover rat, Norway rat, Norwegian rat, or wharf rat (Rattus norvegicus) is one of the best known and most common rats. One of the largest muroids, it is a brown or grey rodent with a body up to 25 cm (10 in) long, and a similar tail length; the male weighs on average 350 g (12 oz) and the female 250 g (9 oz). Thought to have originated in northern China, this rodent has now spread to all continents, except Antarctica, and is the dominant rat in Europe and much of North America—making it the most successful mammal on the planet after humans. Indeed, with rare exceptions the Norway rat lives wherever humans live, particularly in urban areas.
Selective breeding of Rattus norvegicus has produced the laboratory rat, an important model organism in biological research, as well as pet rats.

Description

The fur is coarse and usually brown or dark grey, while the underparts are lighter grey or brown. The length can be up to 25 cm (10 in), with the tail a further 25 cm (10 in), the same length as the body. Adult body weight averages 350 g (12 oz) in males and about 250 g (9 oz) in females, but a very large individual can reach 500 g (18 oz). Rats weighing over 1 kg (2.2 lb) are exceptional, and stories of rats as big as cats are exaggerations, or misidentifications of other rodents such as the coypu and muskrat.

Brown rats have acute hearing, are sensitive to ultrasound, and possess a very highly developed olfactory sense. Their average heart rate is 300 to 400 beats per minute, with a respiratory rate of around 100 per minute. The vision of a pigmented rat is poor, around 20/600, while a non-pigmented (albino) with no melanin in its eyes has both around 20/1200 vision and a terrible scattering of light within its vision. Brown rats are dichromates who perceive colors rather like a human with red-green colorblindness, and their color saturation may be quite faint. Their blue perception, however, also has UV perceptors, allowing them to see ultraviolet lights that some species cannot.

Habits

The Brown Rat is usually active at night and is a good swimmer, both on the surface and underwater, but unlike the related Black rat (Rattus rattus) they are poor climbers. Brown rats dig well, and often excavate extensive burrow systems. A 2007 study found brown rats to possess metacognition, a mental ability previously only found in humans and some primates.

Diet

The brown rat is a true omnivore and will consume almost anything, but cereals form a substantial part of its diet.

Foraging behavior is often population-specific, and varies by environment and food source. Brown rats living near a hatchery in West Virginia catch fingerling fish. Some colonies along the banks of the Po river in Italy will dive for mollusks, a practice demonstrating social learning among members of this species. Rats on the island of Norderoog in the North Sea stalk and kill sparrows and ducks.

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