Final answer:
The smaller a homeotherm, the greater the heat loss due to a higher surface area-to-volume ratio, requiring more energy to maintain body temperature.
Step-by-step explanation:
The smaller a homeotherm, the greater the loss of heat to the surrounding environment. This is due to the fact that small animals, such as mice, have a higher surface area-to-volume ratio compared to larger animals. As a result, smaller homeotherms lose heat at a faster rate and need to expend more energy to maintain a constant internal temperature. This is particularly relevant in extreme climates, such as the poles, where you would not expect to find small homeotherms like wild mice due to the high energy demands to stay warm. The concept of body size affecting heat retention and loss is a fundamental principle in understanding animal physiology and adaptations.