LEXINGTON, Va. — After studying tick infestations for 20 years, Holly Gaff scoffed at the idea of using robots to kill the blood-sucking, disease-causing pests.
But that was before she got her hands on one.
Gaff recently finished the first round of experiments on technology developed by a team of Virginia Military Institute engineers.
The results surprised her as much as it did those who designed it. The robot killed 75 percent of ticks during the least effective trial at a wildlife preserve trail in Portsmouth. On the rest, it completely wiped out the population — all without spraying dangerous chemicals.
Gaff said that before the experiment, people on the trail would find ticks on themselves within five minutes. After the robot’s work, “we were able to sit in the middle and have a picnic after we ran it, with not a tick bothering us,” she said.
At a time when the number of ticks in Virginia is on the rise, and with it the diseases they carry, an environmentally friendly product like this has the potential to reshape the way experts think about pest control.
Gaff said new breeds of ticks are coming to the area from both the south and north. The bugs are a nuisance and can make you sick, most notably with Lyme disease.
The Virginia Department of Health reported 202 cases of Lyme disease statewide in 2003. By 2010, there were 1,245. Southwestern Virginia alone saw 14 cases by May of this year.
The robot’s developers hope to bring it to market within the next few years and say it could one day be considered an industry standard.
“Pest control companies, their business model is to strap toxic chemical tanks on the backs of minimum-wage employees and have them spray,” said James Squire, a VMI electrical engineer who headed the project. “They don’t have any high-tech infrastructure to take care of robots and to maintain them. So it’s a different business model.”
The robot idea came from three engineers at VMI. Squire worked on the electrical components, Jay Sullivan the mechanical and Dave Livingston the computers. A team of undergraduate students also helped design the machine.
The prototype looks like a glorified remote control car dragging a piece of fabric. But Squire explained it was carefully designed to use the ticks’ own predatory instincts against them.
Ticks can live for three years, but feed only two or three times in their lives. They spend most of their days out of sight, buried underground around plant roots to stay moist, according to Gaff.
But in June and July, the height of the tick season, they get hungry and come out of hiding.
That’s when they go to work with their impressive arsenal of biological tools. Gaff said ticks’ feet are equipped with an organ that can smell carbon dioxide from up to 65 feet away. They can also sense small variations in temperature. So if you walk near a tick, it will sense the changes in ground temperature where you step and the carbon dioxide from your breath.
“Ticks are born predators,” Squire said. “They’re really like the Predator in the movie.”
Before the robot starts its work, a tube is stretched around the areas where ticks like to congregate — usually around the edges of a yard away from thick grass. The tube releases carbon dioxide for 15 minutes, drawing all the surrounding ticks to one place.
“We’re not used to seeing ticks run because they’re being so careful about their energy budget,” Squire said. “When you put down carbon dioxide, they race to it and they line up on it. It looks like a conga dance running right across the tube.”
Next, the robot uses sensors to self-navigate over the tube. It drags behind it a piece of denim — ticks’ favorite material, according to the VMI researchers — infused with a common insecticide.
When the fabric gets close, ticks sense its motion, heat from friction and the carbon dioxide. They think it’s an animal, latch on and are killed by the poison.
The robot won’t permanently eliminate ticks because more are constantly coming up from the ground, but Gaff said her experiments showed about 24 hours of relief.
She tested it at the Hoffler Creek Wildlife Foundation and Preserve in Portsmouth. The trails there have been plagued with one of the most severe tick infestations she has ever seen. Local schools even stopped taking field trips to the area because too many kids were coming home with the bugs.
After the robot roamed for about an hour, Gaff said, the treated area was safe for children.
Now that they see their product can work, the VMI engineers have teamed up with Elizabeth Baker, an entrepreneur who teaches at Wake Forest University, to try to commercialize the technology.
She said the next step will be to seek about $200,000 in grants to finish the design. They will then license their product to manufacturers who would create it for pest control companies such as Orkin.
“There is huge interest from the people we’ve talked to,” Sullivan said. “Because people don’t feel like they can go in their own backyard.”