Animals that are cold-blooded are referred to as ectotherms. These animals regulate their body temperature through external environmental conditions, as they lack the internal mechanisms to maintain a constant body temperature like warm-blooded animals do. Ectothermic animals include reptiles, amphibians, fish, and many invertebrates. Their activity levels and metabolic rates often depend on the temperature of their surroundings; they may become sluggish or inactive in cooler temperatures and more active in warmer conditions. This characteristic influences their behavior, habitat preferences, and survival strategies.