Snakes have often been labeled “Unable to Hear” because they have no visible ear on their body.

It has been discovered though, that they have an inner ear, similar to any other ear. They use this to listen for noises of an impending dinner date.

In a 2008 article posted in Physical Review Letters* scientists from the Technical University Munich (TUM), Germany, and the Bernstein Center for Computational Neuroscience (BCCN) present evidence that snakes use this structure to detect minute vibrations of the sand surface that are caused by prey moving. Their ears are sensitive enough to not only “hear” the prey approaching, but also to allow the brain, i.e., the auditory system, to localize the direction it is coming from. The work was carried out by J. Leo van Hemmen and Paul Friedel, scientists at the Biophysics Department of the TUM and BCCN, together with their colleague Bruce Young from the Biology Department of Washburn University at Topeka (KS, USA).

Hear is an excerpt from that article.

“Any disturbance at a sandy surface leads to vibration waves that radiate away from the source along the surface. These waves behave just like ripples on the surface of a pond after a stone is dropped into the water. The sand waves, however, propagate much quicker (the speed is about 50 meters per second) than at the water surface but on the other hand much more slowly than for instance in stone (or concrete) and the amplitude of the waves may be as small as a couple of thousands of a millimeter.

Yet a snake can detect these small ripples. If it rests its head on the ground, the two sides of the lower jaw are brought into vibration by the incoming wave. These vibrations are then transmitted directly into the inner ear by means of a chain of bones attached to the lower jaw. This process is comparable to the transmission of auditory signals by the ossicles in the human middle ear. The snake thus literally hears surface vibrations.

Mammals and birds can localize a sound source by comparing the arrival times of sounds that arrive at the right and left ear through air. For sound coming from the right, the right ear will respond a fraction of a second earlier than the left ear. For sound coming from the left, the situation is exactly the other way around. From this time-of-arrival difference, the brain computes the direction that the sound comes from.

Combining approaches from biomechanics and naval engineering with the modeling of neuronal circuits, Friedel and his colleagues have shown that the snake can use its ears to perform the same trick for sound arriving through sand. The left and right side of the lower jaw of a snake are not rigidly coupled. Rather, they are connected by flexible ligaments that enable the snake to stretch its mouth enormously to swallow large prey. Both sides of the jaw can thus move independently, just like two boats floating – so to speak – on a sea of sand, and in this way allow for stereo hearing.

A sand wave originating from the right will stimulate the right side of the lower jaw slightly earlier than the left side, and vice versa. Using a mathematical model, the scientists calculated the vibration response of the jaw to an incoming surface wave. They could show that the small difference in the arrival time of the wave at the right and the left ear is sufficient for the snake’s brain to calculate the direction of the sound source.

The extraordinary flexibility of the lower jaw of snakes has evolved because being able to swallow very large meals is a big advantage if food is in short supply and competition fierce. Moreover, the separation of the sides of the lower jaw also allowed this very interesting form of hearing to develop.”

*Auditory localization of ground-borne vibrations in snakes. Physical Review Letters 100, 048701 (2008). doi: 10.1103/PhysRevLett.100.048701

Paul Friedel₁, Bruce A. Young₂, and J. Leo van Hemmen₁

1. Physik Department T35, Technical University Munich, Garching (Germany) & Bernstein Center for Computational Neuroscience – Munich (Germany)
2. Department of Biology, Washburn University, Topeka (KS, USA)

Now you can all remember from your parents teachings that if you are walking through the bush, to tread heavy and hit the ground with a stick. This causes the vibrations that snakes interpret as dangerous right? So if those vibrational frequencies can be replicated then chances are the snake would see them as the same danger and disappear.

It’s interesting to note that the snakes will only pick up the vibrations by resting its jaws on the surface of the ground, which lends weight to the fact that it is listening to the vibrations through the ground and not through the air!

Find out more about what you can do about SNAKE DETERRENT

How can Snake Deterrent Work?

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Snake bite nearly kills horse

The recent very wet weather in the Eastern States of Australia have made perfect environment for snakes.
The floods in Queensland have deprived snakes of food for a few weeks now and they are hungry and some cases still clinging on to any bit of high ground they can to stay out of the water.
All this means that when the flood waters recede the snakes will be looking for food and a new place to live.

ROCKHAMPTON: a huge brown snake rests on a garden fence in Depot Hill Picture: Lyndon Mechielsen Source: The Courier-Mail

This article by Peter Michael in Brisbane’s Courier Mail highlights the need to be on the look out.

http://www.couriermail.com.au/news/time-to-hightail-it-out-of-town-as-snakes-search-for-high-ground/story-e6freon6-1225980649882

Be very vigilant when walking around your back yard especially if the grass is long.

Just yesterday I was laying on the grass watching my son ride his scooter in the skate park on the Gold Coast, Australia. I was looking at my phone which I held in my hand and the ear plug cable was stretched out on the ground. I felt a movement on the cable and looked to see a brown snake about to slither over my leg (thigh) on its way to a dam for a drink. Needless to say that is the fastest I have moved this year and the snake just kept on its way to the dam.
So be aware when in the yard, snakes are out and they aren’t scared off just because something big is in front of them.

For anyone who has bought a snake repeller, check to make sure it is working. You will hear it buzz every 45 seconds or so. If you do happen to see a snake passing through your yard, let it go. It not there to take up residence and it won’t stay around if you have a sentinel electronic snake repeller.

Snakes and Floods

Get your FREE report on what you should be doing around your yard to stop snakes from coming around.

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Snakes and Dogs don’t mix