The interactions between members of the same species are known as intraspecific relations and these are frequently very strong varying from open conflict to gregariousness. There are differences between species, of course. Some species, like moose, being quite solitary, have little association with others of their own species. While some animal populations’ exhibit varying degrees of social organization. Many species exhibit territoriality, i.e., individuals compete for the ‘rights’ over some portions of their habitat. The winner uses the territory and the loser has to leave. The area in which an animal lives, eats and functions is known as its home range. Territories and home range vary in size. Territories may cover several miles in the case of large animals or birds or, may be limited to a single plant in the case of some insects. Territoriality serves to diminish destructive competition for resources such as food or habitat by limiting the number of organisms of a species in a given area.

Intraspecific relations are also expressed in patterns of hierarchy in species. The most familiar example is the ‘pecking order’ in chicken. At the top of the pecking order is the chicken that can dominate all others and is not dominated by any while feeding. In the middle are some chicken that are pecked by some and in turn peck others. At the bottom is the chicken that all other chicken can dominate and peck but which cannot peck any chicken. These dominant – subordinate relationships are more prominent when the choice for mates arises. Extreme social organization is found in the structure of colonies of insects like termites, ants and bees.