Final answer:
Mammals are most likely to exhibit panting as a way of cooling down, through the evaporation of water from their tongue and mouth surfaces.
Step-by-step explanation:
The type of animal most likely to exhibit panting is a mammal. Mammals have several ways of regulating their body temperature. When it comes to staying cool, mammals lose excess heat by increasing blood flow to the skin or through behaviors such as sweating or panting. Sweating involves the evaporation of sweat on the skin, which cools the body. However, many animals with fur, like dogs, primarily rely on panting to cool down. Panting allows for the evaporation of water from the tongue and other moist surfaces within the mouth and throat, which utilizes heat from the body and helps in cooling it down. In contrast, other groups such as fish, birds, and reptiles use different mechanisms for temperature regulation and typically do not pant.