How is a cold-blooded animal defined?

A cold-blooded animal, also known as an ectotherm, is defined by its inability to maintain a constant body temperature independently of the environment. Instead, its body temperature fluctuates with the ambient temperature. This means that when the surrounding temperature rises, the body temperature of a cold-blooded animal will also increase, and it will drop when the surrounding temperature decreases.

This characteristic is crucial for understanding how cold-blooded animals interact with their habitats. They often rely on external sources of heat, such as the sun, to warm themselves and become more active, which includes foraging and swimming. Conversely, in cooler weather, their metabolic processes slow down, leading to lower activity levels.

The other options, while related to temperature regulation, do not accurately reflect the definition of cold-blooded animals.