A hamster is a small, furry rodent that many people keep as a pet. Hamsters are about the size of a tennis ball, with soft fur (usually brown, white, gray, or golden), tiny ears, short legs, and almost no visible tail. They have pouches in their cheeks that can stretch enormously, letting them stuff food inside to carry it back to their nest, sometimes making their heads look twice as big.

In the wild, hamsters live in burrows underground in dry areas of Europe and Asia. They're nocturnal, meaning they sleep during the day and become active at night, which is why pet hamsters often start running on their wheels right when you're trying to fall asleep. Hamsters are also famous for being hoarders: they collect and store far more food than they could possibly eat, packing it into the corners of their cages.

As pets, hamsters need cages with plenty of space, exercise wheels, tunnels to explore, and things to chew on since their teeth never stop growing. They're generally solitary animals who prefer living alone rather than with other hamsters. While they're popular first pets for children, hamsters require gentle handling and regular care. They typically live only two to three years, making them a shorter commitment than dogs or cats.