Over 70 years ago, Roald Dahl proposed that plants could scream in a fictional story called The Sound Machine. He suggested they could shriek — a high-pitched shriek undetectable to the human ear.

Imagine walking through a field of crops and hearing high-pitched clicks emanating from the plants. While this may sound like science fiction, it’s a reality that scientists are now studying. These ...

Add Yahoo as a preferred source to see more of our stories on Google. During ritual ceremonies, the ancient Aztec civilization used a “death whistle” — a haunting instrument shaped like a human skull.