Sorry, What? Frogs Actually Make This Horrific Noise We Can't Hear

This is the first documented case of "defensive ultrasound" being used by amphibians.

Researchers in Brazil have revealed that some frogs scream at such a frequency that other animals can hear it but it’s completely inaudible to humans.

While they were in the Amazonian jungle studying frogs, researchers noticed something a little off about the frogs.

Small leaf litter frogs were arching their backs, throwing their heads back and opening their mouths wide. All of which suggests that they were letting out some sort of scream or howl but the scientists actually couldn’t hear a thing.

How researchers discovered the sound of screaming frogs

According to Sky News, researchers recorded the frogs using high-frequency audio recorders and actually managed to capture the first documented case of “defensive ultrasound” being used by amphibians.


The researchers at Brazil’s State University of Campinas believe that this sound is a response to predators and could be a call to arms to attract another animal to attack the predator.

When researchers analysed the sound using specialised software, they found that the scream had a frequency of 7 kilohertz (kHz) to 44 kHz. However, humans cannot hear frequencies higher than 20 kHz, which are classed as ultrasound.

Isn’t it just incredible to think about how many sounds are happening around us without us even knowing?

Animals that make sounds that humans can’t hear

Of course, these screaming little frogs aren’t the only animals that human ears can’t hear. According to the National Park Service: “Elephants use infrasound for communication, making sounds too low for humans to hear.

“Because low frequency sounds travel farther than high frequency ones, infrasound is ideal for communicating over long distances.”

Additionally, according to Pets On Mom: “Humans with very acute hearing can hear part of the lower range of bat sounds, but most of them are beyond us. Bats use these sounds to “echolocate” both prey and obstacles in their flight paths.”

Gosh, the animal kingdom is so clever.