Warm-blooded animals have a higher metabolism in warm weather. Warm-blooded animals are more aggressive in captivity. Warm-blooded animals always have a higher blood temperature. Warm-blooded animals normally maintain a fairly constant internal temperature at all air temperatures. Warm-blooded animals are found only in warm climates.
How are warm-blooded animals different from cold-blooded animals?

Options:
- Warm-blooded animals have a higher metabolism in warm weather.
- Warm-blooded animals are more aggressive in captivity.
- Warm-blooded animals always have a higher blood temperature.
- Warm-blooded animals normally maintain a fairly constant internal temperature at all air temperatures.
- Warm-blooded animals are found only in warm climates.

Warm-blooded animals normally maintain a fairly constant internal temperature at all air temperatures.