Here's why:
* Mammals are warm-blooded animals that have fur or hair, give birth to live young, and nurse their offspring with milk.
* Bears are large mammals with thick fur, claws, and a powerful sense of smell.
* Dogs are domesticated mammals that are known for their loyalty and companionship.
* Cats are domesticated mammals known for their independence and agility.
While these animals have many differences, they all share the defining characteristics of mammals.