During ritual ceremonies, the ancient Aztec civilization used a “death whistle” — a haunting instrument shaped like a human skull. Its eerie, high-pitched scream is not just a product of its unique ...

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.

Plants make high-pitched noises that humans can't hear, a study found. When they are stressed, infected, or cut, the plants start clicking frantically. It may be that insects and other animals can ...