Here's why:
* They give birth to live young: This is a defining characteristic of mammals.
* They nurse their young: Jackrabbits have mammary glands and produce milk to feed their offspring.
* They have fur: This helps with insulation and protection.
* They are warm-blooded: Jackrabbits regulate their own body temperature.
So, while they're called rabbits, they're actually part of the mammal family!