Rat Territorial Behavior
One of rat behavior is called as territorial behavior. The attacks by resident rats on strangers, in the experiments are examples of territorial behavior. By a territory is meant a regions defended against members of the occupants species. Among wild Rattus norvegicus, territorial behavior is, except in one type of situation, probably as a rule a prerogative of males.
The exception is the behavior of females with young nesting, when the defense is only of the nest; lactating females may defend their nests against all visitors, regardless of age, sex or familiarity; but the intensity of nest defense varies, for some females allow adult members of their colony, of both sexes, to share their nest with the young. The two kinds of territory are common among mammals. Female R. norvegicus, in the most closely observed experiments, took no part in defending any larger region, and males defend a nest only when cornered in one by another male.
The Rattus norvegicus that be studied defended only the pathways in rat living space; but unlike previous observers, he recorded attacks on female intruders, as well as on males. He also describes the behavior of R. rattus, this species he find defends the whole of its range. Perhaps the difference is related to the different habitats occupied by these rats; norvegicus burrows and moves largely on the ground; rattus is a climber. The intensity of territorial defense by norvegicus evidently varies with the size of the population large groups. according to Telle, are less territorial, and admit strange rats more readily than small ones.
Unlike human properties, the territories of each animal species are rather uniform in a given type of environment. Property holding by human beings is diverse, but territorial behavior of other species is stereotyped. Since territorial behavior is widespred, we must assume that it contribution to the survival of the rat species in which it occurs. The effect of territorial behavior is undoubtedly to disperse individuals or, more usually, pairs and their young or large groups. This prevent increase above a certain density. Perhaps it ensures that some individuals or families live in optimum conditions, even if others, driven from favorable environments, die or are made infertile.