Some major groups of animals are sessile (fixed in place) and like plants move only in certain life-history stages. Space needs lead to fixed or dynamic home ranges, which are defended in some sessile or territorial motile animals. The size of the home range or territory may change seasonally or be different in different age/sex classes. Refuges are needed for hiding from predators, sleeping, storing food, and having and rearing young. .
Food sources are plants (herbivores) or other animals (carnivores), and diets vary from very generalized to very specialized. Many animals are omnivores (plant and animal diets). Herbivores specialize on leaves, seeds, fruits or nectar, with different arrays of adaptations for each type. Leaves are easy to capture but difficult to digest, so leaf-eaters have special adaptations to process cellulose and antiherbivore compounds. Seeds are locally and seasonally abundant, and are often stored by caching for leaner periods. Special adaptations (rodent teeth, finch bill) are needed to crack seed coat. Color vision is an important adaptation to locate flowers and fruits for both nectar- and fruit-eating, with much coevolutionary fine tuning for these pollinating and seed-dispersing interactions. There are just as many specialized sets of adaptations for carnivory, including those for finding and capturing plankton, mollusks, worms, termites, butterflies, fish, snakes, birds, and other morphologically distinctive taxonomic groups, even carrion. Memory and intelligence are characteristic components of some of these predator adaptations, but there are many other special attributes, such as the use of tools or venom. .
There are many predator-avoidance adaptations, including hiding out of sight or in sight (camouflage); escaping by speed or stealth or immersion in a group; fighting or threat with weapons (teeth, horns); physical protection such as spines or shells; chemical protection such as unpalatability or poisonous bite or sting; and mimicry of unpalatable/dangerous animals.
