Rodents are mammals of the order Rodentia, characterized by a single pair of continuously growing incisors in each of the upper and lower jaws.
Rodents are mammals of the order Rodentia, characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. The name is derived from the Latin rodere, to gnaw. About forty percent of all mammal species are rodents, and they are found in vast numbers on all continents except Antarctica.
They are the most diversified mammalian clade and can be found in a variety of terrestrial habitats, including human-made environments. There are species that are arboreal, fossorial, and even semi-aquatic. Well known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters, but rabbits, hares and pikas, which could be confused with rodents and were once included with them, are now considered to be in a separate order, Lagomorpha.
Most rodents are small animals with robust bodies, short limbs and long tails, but there are exceptions to this. They use their sharp incisors to gnaw food, excavate burrows and defend themselves. Most eat seeds or other plant material, but some have more varied diets. They tend to be social animals and many species live in societies with complex ways of communicating with each other. Mating among rodents can vary from monogamy, to polygyny, to promiscuity. Many have litters of underdeveloped, altricial young, while others have precocial young that are relatively well developed at birth.
Also known as the “sewer rat”. 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). With rare exceptions, the brown rat lives wherever humans live, particularly in urban areas.
Similar to other rodents, brown rats may carry a number of pathogens, which can result in disease, including Weil's disease, rat bite fever, cryptosporidiosis, viral hemorrhagic fever, Q fever and hanta virus pulmonary syndrome. In the United Kingdom, brown rats are an important reservoir for Coxiella burnetii, the bacterium that causes Q fever, with seroprevalence for the bacteria found to be as high as 53% in some wild populations.
The black rat (Rattus rattus) 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 1st century and spreading with Europeans across the world. Black rats are generalist omnivores.
They are serious pests in nature as they eat birds and insects, and to farmers as they eat a wide range of agricultural crops. They are vectors of many diseases including the bacterium Yersinia pestis, an agent of bubonic plague.