Snakes Can Hear Our Screams, New Study Says

Experts have long known that snakes can sense sound vibrations in the ground – called “tactile” sensing – but we wondered if they can also hear sound vibrations in the air, and more importantly, how they react. to sounds.

Read more: Snakes have a clitoris

In a new article published in PLOS One, we come to the conclusion that snakes use hearing to interpret the world, and we disprove the myth that snakes are deaf to airborne sounds.

Our study, which looked at 19 snakes from seven species, reveals that snakes have aerial hearing, but not all species respond to sounds in the same way.

How do snakes react to airborne and ground sounds?

Although sight and taste are the main senses by which snakes perceive their environment, our study finds that hearing plays an important role in the sensory repertoire of snakes.

From an evolutionary perspective, this makes perfect sense. The snakes are threatened by predators including monitor lizards, cats, dogs, and other snakes. Hearing is used to avoid attacks or injuries (for example, by being trampled).

For our experiments, we collaborated with the School of Creative Practice from the Queensland University of Technology to set up a soundproof room and test the snakes one by one.

Using silence as a control condition, we played one of three sounds, each covering a frequency range: 1-150Hz, 150-300Hz and 300-450Hz. For comparison, the human voice typically ranges between 100 and 250 Hz, and birds chirp at around 8000 Hz.

In previous studyresearchers suspended western diamondback rattlesnakes (A terrible rattlesnake) in a steel mesh basket and observed their behavior in response to sound frequencies between 200 and 400 Hz. other studyelectrodes were surgically implanted into the brains of snakes under partial anesthesia to detect electrical potentials in response to sounds of up to 600 Hz.

Our research is the first to study how several species of snakes respond to sounds in a space where they can move freely. We also used an accelerometer to determine if the sounds produced vibrations on the ground. This allowed us to confirm that the snakes did not only feel ground vibrations and did indeed register airborne sounds.

Do snakes move closer or away from sounds?

Most of the snakes showed very different behaviors in the trials with sound compared to the silent moments.

Ramsay’s python (Aspidites ramsayi) – a non-venomous snake found throughout the arid zone of central Australia – began to move more in response to the sound and even approached it. He exhibited an interesting behavior called ‘periscopic’, which involves raising the front third of his body in a way that evokes curiosity.

On the other hand, three other species – Acanthophis (death viper), Oxyuranus (taipan) and Pseudonaja (brown snake) – tended to move away from sound instead, a sign of possible avoidance behavior.

Death Adders are ambush predators. They wait for their prey to come to them using the lure on their tail (which they shake to look like a worm), and they cannot move quickly. It is therefore logical that they move away from the sound. To survive, they must avoid being trampled by large vertebrates such as kangaroos, wombats or humans.

Brown snakes and taipans actively hunt and pursue their prey by day. This means they are at risk of falling victim to diurnal predators such as raptors. In our experiments, these two snakes seemed to have heightened senses. Taipans, in particular, tended to display a defensive and wary attitude in response to sound.

Do snakes hear us?

Our study disproves the myth that snakes are deaf. They can hear, but not as well as you and me. Snakes only distinguish low frequencies, less than about 600 Hz, while most humans hear a much broader spectrum. Snakes probably perceive muffled versions of what we hear.

So can snakes hear us? The frequency of the human voice is between 100 and 250Hz. The sounds used in our study included these frequencies and were broadcast at a distance of 1.2 m from the snakes at 85 decibels. That’s about the volume of a loud voice.

The snakes reacted to these sounds, and several had a strong response. So it can be said that snakes can perceive the voice of people talking loudly or shouting. That doesn’t mean they can’t hear someone talking (a normal conversation is around 60 decibels) – we just haven’t tested at that sound level.