| A | B |
| competition | The struggle between organisms for the limited resources in a habitat. |
| cooperation | Process of groups of organisms working or acting together for common or mutual benefit. |
| social hierarchy | The establishment of dominance-subordinate relationship among higher animal societies. |
| territorial imperative | Drive to take, hold, and defend a particular area, zone, or turf. |
| behavior | All the actions an animal performs. |
| population | Any difference between individuals of the same species. |
| habitat | A classification grouping that consists of a number of similar, closely related species. |
| species | A group of similar organisms whose members can mate with one another and produce fertile offspring. |
| hibernation | A state of greatly reduced body activity that occurs during the winter. |
| migration | The regular, periodic journey of an animal from one place to another and back again for the purpose of feeding or reproducing. |
| circadian rhythm | Behavior cycles that occur over a period of approximately one day. |