Regulate: Homeostasis is maintained by ensuring constant body temperature and constant osmotic concentration, etc., by physiological and sometimes behavioural means. All birds, memmals, few lower vertebrates and invertebrates are endotherms as they have the mechanism of thermoregulation and osmoregulation for maintaining their homeostasis.
Conform: About 99% of animals and almost all plants cannot maintain a constant internal environment. Their body temperature changes with the ambient temperature, i.e. they are ectotherms.
Migrate: If an organism moves away temporarily from a stressful habitat to a more hospitable area and return, when the stressful period is over, the process is called migration.