If we know that animals have a brain and we have a brain, how come we can talk but animals can't?
Well some animals have a brain that is similar to ours but different in a responding way.
For example: A dog will bark and whine. Us,humans, try our best to interpret what the dog wants, but we maybe misinterpret it wrong. Like the dog wants to go outside to pee, but we think he is hungry/thirsty.
Maybe the animal that can talk just doesn't want to be found. Because if it is found, it might be experimented on. If it can talk it has to know alot about other animals/people/things that can talk.
