Static electricity attracts ticks to hosts, scientists find

Ticks can be attracted to air gaps many times larger than themselves by static electricity naturally built up by their hosts, researchers at the University of Bristol have found.

This probably greatly increases their efficiency in finding hosts to parasitize since ticks are unable to jump, and therefore this is the only mechanism by which they can communicate with hosts beyond their reach. small legs.

The findings, published today in Current Biology, are the first known example of static electricity being involved in attaching one animal to another.

Ticks carry many serious diseases, including Lyme disease, which make life difficult for many people and animals, and can cause death. There is therefore considerable social and economic benefit to efforts to reduce the ability of ticks to attach to humans and animals that depend on humans.

Lead author Sam England from Bristol’s School of Biological Sciences explained: “We know that many animals, including humans, can accumulate enormous electrostatic charges.

“We see this when we get a static shock after jumping on a trampoline, or when we rub a balloon on our hair, for example. But this electrostatic charging also occurs in animals in nature when they rub against objects in their environment such as grass, sand, or other animals. These charges are surprisingly high, and can amount to hundreds if not thousands of volts – more than you get out of your plug sockets at home! Importantly, static charges exert forces on other static charges, either attractive or repulsive depending on whether they are positive or negative.

“We wondered if the static charges naturally accumulated by mammals, birds, and reptiles might be high enough that parasitic ticks could be removed from the air by electrostatic attraction to these animals, therefore improving their efficiency in finding hosts to feed on.”

The team initially tested the idea by bringing statically charged rabbit fur and other materials near ticks and observing whether they were attracted to them.

They witnessed ticks being easily pulled through air gaps of a few millimeters or centimeters (the equivalent of people jumping a few flights of stairs) by these charged surfaces, and so investigated further.

Sam continued: “First, we used previous measurements of the average charge carried by animals to mathematically predict the strength of the electric field generated between a charged animal and the grass that wanted to sit and wait for the hosts passing by.

“Then, we placed ticks under an electrode, with an air gap in between, and increased the charge on the electrode until the ticks were attracted to the electrode. By doing this, we determined the minimum electric field strength if to which ticks may be attracted. This minimum electric field is within the order of magnitude predicted by mathematical calculations of the electric field between a charged animal and grass, so ticks are likely to nature is attracted to their hosts by static electricity.

There are several broader implications and potential applications to these findings. First, the phenomenon likely applies to many other parasitic species that like to interact and attach to their hosts, such as mites, fleas, or lice, and so it may be a universal mechanism for animals to communicate and connect with each other. .

Beyond purely scientific implications, the discovery opens the door for new technologies to be developed to reduce tick bites in humans, pets, and farm animals, such as the development of anti-static that spray.

Sam concluded: “We have now discovered that ticks can be removed from air spaces many times larger than themselves by static electricity naturally generated by other animals. This makes it easier for them to find and attach the animals they want to capture and feed. Until now, we had no idea that an animal could benefit from static electricity in this way, and it really opens one’s imagination to how many invisible forces like this can help animals and plants that live their lives.

The team now plans to investigate whether ticks are capable of sensing the approaching electrostatic charge of their prospective hosts.

Role:

‘Static electricity passively attracts ticks to hosts’ by Sam England et al in Current Biology.