African clawed frogs used to be the best human pregnancy tests in the world. Doctors would inject a woman's urine into the back of a female frog; if positive, the frog would lay eggs. Frog or ...

It’s known for its ability to show whether a woman is pregnant. How? Well, by injecting a woman’s urine into the frog’s skin, ...

In a mountain forest of Papua New Guinea, a pregnant creature perched on some leaves near a stream and scanned the area with solid black eyes. But it wasn’t the only one looking around.