Here's why:
* Metabolic Rate: Rats have a high metabolic rate, which generates a lot of heat. They need to stay warm to keep their metabolism going.
* Optimal Temperature: The ideal temperature for a rat is between 68°F and 72°F (20°C and 22°C).
* Cold Stress: If they get too cold, they shiver to generate heat. If they get too cold for too long, it can lead to hypothermia and even death.
* Warmth Seeking: Rats naturally seek out warm places to rest, such as under blankets or in burrows.
However, they can tolerate a range of temperatures. They are more adaptable than many other mammals, and they can survive in temperatures as low as 40°F (4°C) for short periods.
It's important to provide a comfortable environment for pet rats, with a cozy nest and a temperature-controlled space.