Simple Definition:

Mammals are a group of animals that have fur or hair on their bodies, produce milk to feed their young, and give birth to live babies [babies that are born alive and not from eggs].

Examples:

• Dogs, cats, and horses are all mammals because they have fur or hair, produce milk for their babies, and give birth to live puppies, kittens, and foals respectively.
• Humans are also mammals because they have hair, produce milk to feed their babies, and give birth to live babies.

Very Simple Definition:

Mammals are animals that have fur or hair, produce milk for their babies, and give birth to live babies [babies that are botn alive and not from eggs].

Examples:

• Dogs, cats, and horses are all mammals.
• Humans are also mammals.