Their tail has bolder black and white stripes. On their sides, they have chestnut-brown feathers with white spots. Female zebra finches are almost entirely gray and don't sing like the males.

Scientists are puzzling over a boulder on Mars with zebra markings. The black-and-white striped rock is unlike any seen on the Red Planet and has caused excitement among internet users.

The black-and-white striped rock is unlike any seen on Mars before, NASA said this week in a news release. Here's everything to know about the "zebra rock," as well as other recent discoveries ...