Information on Disease from Rats - Part 2

Diseases Directly Transmitted by Rats

• Hantavirus Pulmonary Syndrome. This is a viral disease that is transmitted by the rice rat. This disease is spread in one of three ways: inhaling dust that is contaminated with rat urine or droppings, direct contact with rat feces or urine, and infrequently due to the bite of rat.
• Leptospirosis. This is a bacterial disease that can be transmitted by coming into contact with infected water by swimming, wading or kayaking or by contaminated drinking water. Individuals may be at increased risk of Leptospirosis infections if they work outdoors or with animals.
• Rat-bite Fever. This disease may be transmitted through a bite, scratch or contact with a dead rat.
• Salmonellosis. Consuming food or water that is contaminated by rat feces bacteria can cause this disease.

Diseases Indirectly Transmitted by Rats

• Plague. This disease is carried by rats and transmitted by fleas in the process of taking a blood meal. Domestic rats are the most common reservoir of plague.
• Colorado Tick Fever. This is a viral disease that is transmitted by the bite of a tick that has taken a blood meal from a bushy-tailed woodrat.
• Cutaneous Leishmaniasis. This disease is a parasite that is transmitted to a person by the bite of an infected sand fly that has fed on a wild woodrat.

Hantavirus

Some species of rats such as the cotton rat or rice rat are known carriers of hantavirus. Norway rats and roof rats are not known transmitters of hantavirus. Victims may be debilitated and can experience difficulty breathing. Hantavirus is transmitted to humans when they inhale airborne particles from rodent droppings, urine or carcasses that have been disturbed.

The first symptoms of the virus can be mistaken for the flu. Patients then suffer breathing difficulties that may prove fatal if not treated effectively and immediately.

In order to avoid hantavirus, all mouse feces, nest materials and dead rodents must be removed from the home. Spray suspected areas thoroughly with disinfectant before sweeping to avoid having anything become airborne. Use gloves to handle rodent carcasses or droppings and a respirator must be worn with functioning cartridges. Buildings should be aired out following an infestation. Not all rodents have been found to carry hantavirus. Deer mice, cotton rats, rice rats and white-footed mice are the most common transmitters. However, everyone should use caution in dealing with rodents or rodent infestations and contact a pest control professional.

Information on Diseases from Rats - Part 1

Information on Diseases from Rats - Part 1

Rat bites and scratches can result in disease and rat-bite fever. Rat urine is responsible for the spread of leptospirosis, which can result in liver and kidney damage. It can also be contracted through handling or inhalation of scat. Complications include renal and liver failure, as well as cardiovascular problems.

Lymphocytic choriomeningitis (LCMV), a viral infectious disease, is transmitted through the saliva and urine of rats. Some individuals experience long-term effects of lymphocytic choriomeningitis, while others experience only temporary discomfort.

One of the most historically dangerous rat-borne diseases is the bubonic plague, also called “Black Plague,” and its variants. Transfer occurs when fleas from the rats bite human beings. Fleas transported on rats are considered responsible for this plague during the Middle Ages, which killed millions. From the transmission of bubonic plague to typhus and hantavirus, rat infestations can prove harmful to human health.

Rats also are a potential source of allergens. Their droppings, dander and shed hair can cause people to sneeze and experience other allergic reactions.

Diseases transmitted by rats fall into one of two categories: diseases transmitted directly from exposure to rat-infected feces, urine or bites and diseases indirectly transmitted to people by an intermediate arthropod vector such as fleas, ticks or mites. While the following list of diseases or medical conditions are all associated with rats, most are not commonly encountered in the United States.

Behavior, Diet and Habitat of Rats

Rat Behavior - When rat populations are large, a hierarchy develops within a burrow. Stronger individuals become dominant, while weaker ones are subordinate. Males no longer protect female burrows. When a female is estrous, several males mate with her sequentially, in the order of their social dominance.

Rats exhibit aggressive behavior when threatened. They may fight, chase, bite and box. Rats also display some behaviors such as sidling and belly-up defensive postures.

Rats dwell in cities, suburbs and rural areas. They are capable of thriving in human environments are therefore are considered a commensal rodent. Rats are known to travel great distances and are wary of unknown objects in their established foraging paths. This skepticism can make trapping a rat particularly difficult for a homeowner.

Rat Diet - Rats are fairly opportunistic feeders. They will feed on a array of items from carcasses to fallen fruit. Human environments provide them an abundance of resources. Particular species of rat may have tendency for certain foods. Norway rats often prefer foods high in protein such as meat scraps or pet food. Roof rats usually prefer fruit, which is why people often refer to them as fruit rats. They may be attracted to areas with fruit tress.

When living near humans, the availability of foods will drive a rodent’s habits. They often will travel outdoors and indoors searching for nutrition. They can take advantage of many food sources such as garbage cans, open containers of food, pet food bowls, and they will even cannibalize their own dead. Homeowners should try to eliminate or minimize the abundance of rodent food sources as well as contacting a pest control professional.

Rat Habitat - Rat species are either terrestrial or arboreal in nature, although rats preferring one habitat are capable of inhabiting others. The Norway rat and roof rat are the two most common North American rat species. They are terrestrial and arboreal, respectively.

 Norway rats are most commonly burrowers. They build their nests outside the walls of homes or in various clumps of vegetation. Norway rats may also construct their homes beneath the edges of sidewalks or patios.

As is implied by their name, roof rats prefer arboreal habitats. They live in yucca, palm and cypress trees, as well as in elevated areas of human homes. Roof rats can be found living in attics, rafters, eaves and on roofs. They may also choose to nest in nonarboreal vegetation, such as shrubs, honeysuckle and tall grasses.

Rats

Rats

The most common rats are the black or roof rat and the brown Norway rat. Both species typically live a year or less and can grow in excess of 40 cm.

Effective rat control begins with prevention. All possible entry points, such as sewers and air vents, should be sealed against rodents. Rats can enter through a hole as small as a quarter (25¢), so even very small holes should be sealed. Rats often enter by climbing trees and coming through broken screens or vents.

In order to address an existing rat population, it is necessary to identify and eliminate their feeding, drinking and dwelling sites. Pet food is an incentive for rodents and should be kept in tightly sealed containers. All human food should be stored likewise. Any standing water or moisture leaks should be addressed. Trash should be disposed of properly, and sanitary conditions should be observed. Wood piles and other rodent shelter sites such overgrown weedy areas should be eliminated.

Various rat traps and possible rodenticides are commercially available. However, because rats tend to avoid unfamiliar objects, it is often necessary to enlist the services of a local pest control professional when attempting to control an existing rat population.

Rats are responsible for having been carriers of fleas which spread deadly plagues throughout history. They are still known to be carriers of various diseases. 

Following our blog to learn more about rats!

More Information about House Mice

House Mouse Control Tips

To prevent mice from entering the home, all cracks, crevices, holes and gaps larger than a pen cap should be sealed with cement or a mixing compound. It is not advised that wood be used to seal these holes, as mice are capable of chewing through those surfaces.

Cleanliness may also have an effect on pest infestations. Be sure to wash dishes immediately following use. Food should be stored in glass or metal containers with tight lids. Mice acquire most of their water from scavenged food particles and no crumbs or morsels should be left on tabletops or floors.

When a home is already infested, prevention methods prove inefficient. The most effective mouse control methods are those administered by trainedprofessionals.

More Information on the Common House Mouse

The house mouse is a small mammal named for its propensity to live within human habitats. Next to humans, the common house mouse is one of the most prevalent mammalian species in the world. Native to Asia, these rodents have spread throughout the world. They are most commonly seen living within or near human habitations. They may also be used as laboratory subjects and contribute greatly to scientific studies.

House mice walk, run and stand on all fours. They can stand on the hind legs, as well, and are supported by the tail, which also provides balance while in motion. The house mouse has a sharp sense of hearing and communicates with other house mice through squeaks. Some of these squeaks are audible to humans, while others extend into the ultrasonic range. The common house mouse weighs between 12 to 22 grams and may grow up 20 cm in length. They are black to light brown or gray in color, with short hair and lighter bellies

Signs of a House Mouse Infestation

Signs of a House Mouse Infestation


Sightings - Although more commonly active in the evening, it is possible to see a house mouse roaming in your home during the day. Most often these animals are spotted scurrying along walls or running from a normally undisturbed hiding place.

Droppings - Where there are mice, there are droppings. These small pellets are commonly found anywhere the animals have visited or traveled. Approximately 3 to 6 mm long, the droppings may be rod shaped with pointed ends.

People may confuse house mouse droppings with those of the American cockroach. Even though the general size and appearance of these droppings are similar, mouse droppings usually have hair embedded in them from where the mice have groomed themselves. Roach droppings also are not pointed and usually have ridges running down the sides.

Footprints - As mice explore their territories, they often leave behind footprints or tracks on surfaces. The distinct pattern of a four-toed front foot and a five-toed back footprint are a clear sign that a mouse has passed by.

Gnawing/Chewing - House mice are known for their ability to chew on a wide variety of items. In most cases, shavings and a fresh accumulation of debris is often the first indication of damage. Teeth and gnaw marks can also be found along the edges of frequently traveled routes, on the corners of objects or creating openings into an area.

Burrows/Tunnels - House mice tend to build nests in material that provides a dark and protective environment, such as insulation and other soft materials. These nests are often characterized by openings or tunnels that are free of dust and cobwebs, but may be littered with droppings.

Sounds - During the evening hours, especially when it is dark and quiet, these small animals can often be heard gnawing and scratching within the walls, running across the ceiling and possibly squeaking.

Odor - House mouse urine plays an important role in communicating with other rodents. Oftentimes, rodents will mark an area to attract females or warn off other males. A distinct odor may become noticeable in an area with a large rodent population or when rodents have been present for a long period of time.

Facts about House Mice

House Mice

Appearance - House mice are covered in short hair that is light brown or gray to black in color, with lighter bellies. Their ears and tail also bear hair, although much less than their bodies. Adult mice weigh approximately 12 to 30 grams and can grow up to 20 cm from the nose to the tip of the tail. Droppings are rod-shaped and pointed on both ends.

Behavior, Diet & Habits - Normally, the house mouse makes its home in farm fields, grassy and wooded areas, building nests in areas that are dark and protected from the elements and close to a readily available food source.

Very inquisitive in nature, the house mouse will spend the day roaming its territory, exploring anything new or out of the ordinary. When available, the house mouse prefers seeds and nuts in its diet, but this opportunistic feeder will eat almost anything available.

When the temperatures outside begin to drop, house mice, since they don’t hibernate, begin searching for a warmer place to live. Often attracted by the smell of food and the warmth of a structure, the house mouse can use any opening, such as utility lines, pipe openings, and gaps beneath doors, to gain entry into a home.

Reproduction - The house mouse is known for its ability to reproduce very quickly. A single female is capable of producing up to eight litters per year with an average of six pups per litter. After a 21-day pregnancy, these house mouse pups are born naked, blind and dependent upon their mother for everything. At about 21 days the young are weaned from their mother and may begin to take short trips away from the nest to explore their surroundings. Most mice reach sexual maturity at about 35 days of age and begin mating when they are six weeks old.

Black Widow Spider

Black Widow Spider

The Black Widow spider is the most poisonous spider in North America, but only the adult female.

The female Black Widow is easy to recognize (if you care to get that close) by the red hourglass shape on the underneath part of her abdomen. She has a shiny black body with various types of red markings on the top, depending on the species. There are about five species of Black Widow spiders in North America.

The black widow will grow to about 8-10mm.

Black Widows will lay up to 400 eggs at a time, but they are known to be cannibals, which means that they will eat each other. The Black Widow has unfairly earned a bad reputation for wanting to eat her mate. She will only eat her mate when she mistakes him for a meal!

The silk of this spider is known to be the strongest of all silk. The Black Widow spider does not spin the pretty webs, instead she will spin the thick jumbles looking cobweb. These webs catch beetles, flies, grasshoppers, moths and other spiders.

These spiders, although a little scary, have enemies, as well. A few wasps can sting and paralyze, before eating the Black Widow. She is also a favorite food of the Praying Mantis. Some birds will eat these spiders but could end up with an upset stomach from her poisons. The bright red markings on her belly will warn possible predators that she is a nasty meal.