Snake sensitivity to electric potentials

[Turtle]

Just for starters, what is the impedance of a snake?

 

Frank, I can't find specific measures for snakes, but here's a few links on measuring impedance in tissue. Maybe we can induce one our snake-keepers to try some experiments? :friday:

 

Tissue impedance spectra and the appropriate frequencies for EIT

 

http://www.cnm.es/~mtrans/PDFs/an-integrated-circuit.pdf

 

Bodystat

[FrankM]

The Bodystat web site mentioned didn't require inserting a probe into the tissue, but even then it is somewhat more complicated than mentioned in that article. The pure resistance measurements are the easiest as they are performed with a constant dc potential. The ac impedance is dependent upon the frequency of the applied potential, and they state that 50Hz is typically used.

 

Seismic currents at any given point on the earths surface above and near a seismic event will be the vector sum of all the components from the source, which is not a point source, and will have varying degrees of intensity during the event. A potential created by the radial currents will be a varying dc which introduces an ac component. The "Stray Voltage Field Guide" provides some insight in why snakes might be reacting sooner than larger creatures.

 

http://www.uwex.edu/uwmril/pdf/StrayVoltage/Stray_Voltage_Field_Guide.pdf

 

It thus took about 10 times the current to elicit a response from a cow than from a person. This is mainly due to the smaller cross section of humans when compared to cows.

 

A snake has a significantly smaller cross section, but we cannot state unequivocally whether they are 10 or 20 times more sensitive to a particular current than a human, U.S. biologists won't measure it.

 

The precursor currents will function like pulsed dc and this will effect how a biological entity reacts. From the cited URL:

Animal and human sensitivity is very different for these three categories of voltage and current. The easiest way to determine the ability of an electrical pulse to excite nerves is to specify its phase duration and peak current.

It then states that when the voltage appears as a "step potential" the animal response increases. Since seismic induced currents are not pure dc we can't predict exactly how various creatures will react, but I suspect they will exhibit "step" components.

[FrankM]

An individual that is located in Japan provided the following URL, which identifies an observation by a Japanese scientist.

 

Interview with Dr. Motoji Ikeya

 

Dr. Ikeya: The Kobe earthquake in 1995. I live 30 km from the epicenter and thought it strange that many earthworms dug themselves up in my small garden. At the time, I did not know the legend that a number of emerging earthworms is a sign of a large earthquake. Many people noticed this, including my neighbors.

 

If you put "worms electricity" into your favorite search engine you will find many articles where it describes how various electrical sources or devices are available to "shock" worms to the surface. I don't think it takes a rocket science to also see a linkage between underground electrical currents and snakes, but no one is examining precisely what current levels will make a snake react. I would suspect worms are much more "conductive" than snakes, but there seems to be no research in this area.

 

We know from the research by Friedemann Freund that precursors and earthquakes produce a low frequency current pulse. What instruments can we use to detect this "current" that is being felt by worms and snakes?

[FrankM]

I have a raised garden bed which I prepare in the Fall for Spring planting and it is prolific with worms. To see if worms will respond to an electrical current in the soil I stripped some #12 solid copper wire to use as electrodes and then found a 38.7V DC power transformer that had been used to power an HP printer, since scrapped. I inserted the electrodes 15.2 cm (6") into the ground with a 25.4 cm (10") separation. I placed a meter in series to measure current and this resulted in a 65 milliamp (ma) current.

 

Within 60 seconds (worms don't move fast) I had multiple worms exiting from the ground, more closer to the electrodes. I moved the electrodes around in the planting bed to have a fresh area as I varied the electrode spacing, equivalent results were observed with just 20 ma. The next day I obtained a 12 VDC and a 9 VAC transformer and repeated the experiment. I put a low ohm resistor in series with the AC so I could measure the voltage drop and calculate the current. The 12 VDC gave me an approximate 22 ma current, with 25 cm spacing, and when I switched to the AC source (voltage across electrodes 8.7 V) with in-line resistor gave approx. 15 ma.

 

Worms would exit not only between the electrodes but in areas that were not between them (on the backside), this for both AC and DC.

 

I do not know what minimum current would cause worms to exit the ground. My crude experiments suggests that this will be different between AC and DC. I varied my electrode contact with the ground to get a little as 3 ma. with a 25 cm separation and I had worms exiting. Even after surfacing the worms remained agitated until they removed themselves way from the area near or between the electrodes. My only previous experience with worms being agitated was when they were applied to a hook for fishing.

 

When DC was applied it appears more exited from the ground near the negative terminal than the positive, but I wouldn't want to make any conclusions on that issue without a controlled study.

 

When I was searching for information on whether anyone had studied the issue of worm sensitivity to electric currents I found reports of devices being used to extract worms to obtain "worm counts", but nothing on sensitivity per se. The most sophisticated worm extraction device was the use of an "electrofisher" and the crudest 120 VAC directly from a portable generator, this by Univ. of Notre Dame biologists.

[Turtle]

I have a raised garden bed which I prepare in the Fall for Spring planting and it is prolific with worms. To see if worms will respond to an electrical current in the soil I stripped some #12 solid copper wire to use as electrodes and then found a 38.7V DC power transformer that had been used to power an HP printer, since scrapped. I inserted the electrodes 15.2 cm (6") into the ground with a 25.4 cm (10") separation. I placed a meter in series to measure current and this resulted in a 65 milliamp (ma) current.

 

Within 60 seconds (worms don't move fast) I had multiple worms exiting from the ground, more closer to the electrodes. ....

 

When I was searching for information on whether anyone had studied the issue of worm sensitivity to electric currents I found reports of devices being used to extract worms to obtain "worm counts", but nothing on sensitivity per se. The most sophisticated worm extraction device was the use of an "electrofisher" and the crudest 120 VAC directly from a portable generator, this by Univ. of Notre Dame biologists.

 

Excellent experiment Frank! And unlike the notre dumb guys, yours was safe. :hyper:

 

I have a question that may or may not give some measure of the worms sensitivity. When the electro-stimulated worms "removed themselves way from the area near or between the electrodes.", did they show a preference for their direction of exit in regard to the geometric line between the electrodes? That is did they move preferentially parallel or at particular angles from that line? Was this any different a condition depending on when you used AC or DC?

 

Years ago while reading an old encyclopedia in the E's, an article on a topic that began with 'electro-' and ends in I have completely forgotten. :doh: Anyway, the article said this 'electro_____' effect is such that if you pass a low voltage DC current across/through an aquarium, the fish will begin to swim back & forth in the tank parallel to the geometric line between the electrodes.:shrug:

 

Just though the worms and or snakes might also show such a preference. :)

[FrankM]

Excellent experiment Frank! And unlike the notre dumb guys, yours was safe.

What I found from the Notre Dame biologists report is that I know "zilch" about worms. They identified there are two types of worms, one a horizontal burrower and the other a vertical burrower. One might rationalize that a vertical burrower would find a faster exit from the ground than one that has horizontal burrows, but I don't know which types exited from my garden soil. All I know I have "red worms" and another type that is not red but are much longer than red worms. (Not nightcrawlers) The ND biologists were doing a legitimate study to determine whether "electro-extraction" was an effective method of determining valid worm counts. Their improvised "worm getter" may have paralyzed some worms preventing them from escaping to the surface, others may have burrowed down.

 

http://www.nd.edu/~underc/east/education/documents/OsterholzW_2006_earthwormextractiontechniques.pdf

 

I have a question that may or may not give some measure of the worms sensitivity. When the electro-stimulated worms "removed themselves way from the area near or between the electrodes.", did they show a preference for their direction of exit in regard to the geometric line between the electrodes? That is did they move preferentially parallel or at particular angles from that line? Was this any different a condition depending on when you used AC or DC?

 

There were some differences between the AC and DC extractions, but I didn't spend enough time with the AC source to establish whether I could conclude the differences were consistent.

 

Most worms would seek a surface direction that was away from the electrodes (when not between the electrodes), or if somewhat between the electrodes, they would generally move in a direction somewhat near 90 degrees away from between the electrodes. I deliberately placed some worms that had exited and moved away from the "current zone" directly between the electrodes to see their reaction (would they seek a minimum potential path?), and I found if they did not find a rather immediate direction away from this "zone" they would become moribund, apparently paralyzed. After moving the moribund worms away from the center current path they recovered. Worm size seemed to be a factor as bigger worms move faster, thus don't stay in the center area as long.

 

The basic issue was whether a sustained electric current, AC or DC, would cause worms to exit the ground. It did. A seismic generated electric current would cover an extended area so worms (or snakes) really can't escape from it. It would be of academic interest to know if worms (or snakes) have a potential sense or if they are just reacting to what is a greater or lesser potential across their bodies.

[FrankM]

I must note that worms were not the only soil occupants that exited when a sustained electric current was applied to a soil area. Exiting in the same area as the worms were small centipedes, which I learned are beneficials. I did not know I had that many in my garden beds, and it indicates that these insects are also sensitive to earth currents.

 

Centipedes have many legs and these are the primary contact elements to the earth. I must mention that earthworms have almost invisible hairs or bristles that provide the "holding" that allows worms to move forward or backward, but they also provide an added contact with the earth which might be a factor in their "sensitivity".

 

I didn't work with the AC current as much as the DC and I don't recall seeing any centipedes while working AC, but this may be due to my concentration on worms. I can conclude that centipedes are sensitive to an applied DC current.

 

I do not know their minimum sensitivities.