Laboratory Rats

Most scientific studies of rat behavior have been on domestic varieties of Rattus norvegicus. All laboratory rats are of this species. They can easily be crossed with wild ones, but their behavior differs from that of wild rats in many important respects, not all of them obvious.

They have been selected for tameness that is for a reduced tendency to flee from man or to struggle or bite when handled. In addition, strange objects which would in duce avoidance (fear) by wild rats provoke mainly approach (curiosity) by tame ones; and tame males do not attack other males with anything like the same intensity as wild males.

Their selection of food, when they are faced with a choice, may also differ from those wild rats. A similarity of behavior, which they are rarely allowed to display, is that they burrow readily.

Differences in behavior have been paralleled by changes in growth, described by Donaldson. There are differences in the relative weights of organs, such as the adrenal glands. A population of wild rats is genetically heterogeneous, and generalizations about the behavior of wild rats often have to be qualified by reverence to individual variation.

In an inbred strain genetically variation is greatly reduced. This has advantage, for certain kinds of experiment, that differences between experimental and control group are more likely to be the effect of the experimental procedure, and less likely to be due genotype variation with which the experimenter is usually not concern.

Rat Species

What is rat? rat is always come to my house, in a village, in the city, even in modern house, rat will come to you. A common kind of rat is a brown or black rat that often seen in our environment. Black rat have a species name Rattus rattus and a brown rat have a species name Rattus norvegicus that is originated in Asia. Rat exactly the name of small mammal that usually are not include in rat species like in America as Nort American pack rat and in Australia called as kangaroo rat and many others. Other kind of rat also include Bandicoot rat that are not exactly include as Rattus genus, this kind of rat is a murine rodent that related to true rat are a minority in this diverse genus.

In a Western country rat sometime become a domestic rat as pets, these rat is a species Rattus Norvegicus which originated in greensland of China and spread to Europe. The common rat that live in our neighborhood are opportunistic survivor, and often live with or near humans. A black plague is believed cause by microorganism of Yersinia pestis that is carried by tropical Rat Flea. (Xenopsylla cheopis), this rat live in European cities that become a plague themselves.

While modern wild rats can carry Leptospirosis and some other "zoonotic" conditions (those which can be transferred across species, to humans, for example), these conditions are in fact rarely found (not true in neotropical countries). Wild rats living in good environments are typically healthy and robust animals. Wild rats living in cities may suffer from poor diets and internal parasites and mites, but do not generally spread disease to humans.