It's easy to think of pupils as simple holes that widen in the dark and shrink in the light. But if you look across the animal kingdom, you'll see a variety of pupil shapes: vertical slits in cats and ...

Frog and toad pupils come in quite the array, from slits to circles. But overall, there are seven main shapes of these animals’ peepholes, researchers report in the Aug. 25 Proceedings of the Royal ...

Hello all, it’s Manasee Wagh, service and news editor at PopMech. Years ago, I had a cat named Cyrus. I used to stare at him staring at me, and wonder what he was thinking. He had beautiful gold-green ...

Rayna Bell, a herpetology expert and curator at the California Academy of Sciences, told Snopes it's true that some frogs have heart-shaped pupils, adding that the photo in question appears to be a ...