why do you think it is an effective device to use animals (and animal references) to relay a message about human behavior?

To observe animals' behavior and to use animals' references is important to understand human behavior.

Explanation:

When people try to figure out a behaving of an animal, or its signal, they are trying to learn the meaning of those signals, the same way they read or listen to someone talking.

People try to understand the meaning of an animal's sign. This is important for people because, in this way, people are learning about themselves and their cognitive abilities. Animals and humans make an inseparable evolution line.