As nature’s siren call beckons us outdoors this summer, there’s a whole host of creepy crawlers waiting to bite us.
For instance, there’s the not-so-humble tick. These close relatives of spiders like to bite on anything with a pulse. Some species, like the black-legged (or deer) tick, transmit devastating maladies like Lyme disease. For their small size, ticks can do a lot of damage, and it appears their skill in finding unsuspecting hosts might lie in static electricity.
Ticks can’t jump or fly, but what researchers at the University of Bristol in the UK propose is that these wily arachnids take advantage of the electrical fields generated when we or other animals interact with our shared environment. The researchers found that ticks can sense and respond to these invisible electrical threads, allowing themselves to be hooked as if on a fishing line and reeled in onto their hosts. The results of these findings were published Friday in the journal Current Biology and may point to better anti-tick defenses.
“We wondered whether the static charges that mammals, birds, and reptiles naturally accumulate could be high enough that parasitic ticks could be lifted through the air by electrostatic attraction onto these animals, therefore improving their efficiency at finding hosts to feed on,” Sam England, the study’s lead author formerly of the University of Bristol and now a biologist at the Natural History Museum in Berlin, said in a press release.
To do that, England and his colleagues tingled tick spidey senses — specifically castor bean ticks — by rubbing rabbit fur on acrylic surfaces generating static electricity. Nearby arachnids were yanked anywhere from a few millimeters to a few centimeters through the air to these statically charged surfaces. The distance is comparable to us jumping up several flights of stairs.
Next, 20 young ticks, or nymphs, were placed on an aluminum plate close to a small, round metal electrode. When the electrode had a voltage similar to that found on vertebrates (around 750 volts), three out of four ticks were able to jump the gap. When there was no charge on the electrode, none of the ticks crossed.
Playing around with the voltage and distance between plate and electrode, the researchers also discovered, eerily enough, that even dead ticks could be lifted by an electric field similar to that emitted by human skin from a distance of about 10 centimeters (or four inches) away.
The ticks were attracted to both positive and negative electrical fields, suggesting their bodies are polarized — containing separate negative and positive charges — although how exactly this polarization works isn’t abundantly clear.
The researchers believe these findings may help us figure out ways to thwart the arachnid’s parasitic lust. For example, applying anti-static coatings to livestock, pets, or human clothing to reduce tick interactions.
Said England: “Until now, we had no idea that an animal could benefit from static electricity in this way, and it really opens up one’s imagination as to how many invisible forces like this could be helping animals and plants live their lives.”