Külmaverelised
Külmaverelised, also known as ectotherms, are animals that rely on external sources of heat to regulate their body temperature. This contrasts with warm-blooded animals, or endotherms, which generate their own internal heat. The term "cold-blooded" is somewhat misleading as the body temperature of an ectotherm can vary significantly depending on the environment, and can be quite warm when exposed to sufficient heat.
Ectotherms achieve thermoregulation through behavioral means. For instance, reptiles like lizards will bask in the sun
The metabolic rate of ectotherms is generally lower than that of endotherms, meaning they require less food