Ectothermy is a biological term that describes organisms that rely on external environmental conditions to regulate their body temperature. Unlike endothermic animals, which generate heat internally, ectothermic creatures, such as reptiles, amphibians, and fish, absorb heat from their surroundings. This means their activity levels can vary significantly with changes in temperature. Ectothermic animals often bask in the sun to warm up or seek shade to cool down. Their metabolic rates are influenced by the temperature of their environment, which can affect their growth, reproduction, and overall behavior. This adaptation allows them to thrive in various habitats but also makes them vulnerable to extreme temperature changes.