Respuesta :

Cold blooded animals won’t just become warm blooded overnight. They probably would take hundreds to thousands of years to adapt. The reason they probably wouldn’t change to warm-blooded is because they have adapted to being cold-blooded. They wouldn’t need to change, since most cold-blooded creatures are find with maintaining homeostasis that way.
They could and it's not impossible. It is just that it might take thousands of years for it to happen. They need to go through the process of evolution.

It also does not happen often because if an animal is cold blooded it is because it adapted to be so, because it suits the environment the animal is in best.

Hope it helped!