The tick, an easy prey for ants, can detect their proximity through chemical signals, suggesting that these same signals could be used in humans as insect repellent

The tick, a vulnerable prey for ants, has the ability to detect their proximity through chemical signals, according to a study published on Wednesday. This discovery suggests that these signals could potentially be used in humans as insect repellent, especially against species that are vectors of diseases such as Lyme disease.

In the United States, the Ixodes scapularis, also known as the deer tick, feeds on the blood of deer. In the absence of deer, it turns to passing humans, increasing the risk of transmitting various pathogens, including that of Lyme disease, which can cause symptoms ranging from simple itching to neurological disorders.

In Europe, Ixodes ricinus, a cousin of the deer tick, plays the role of a vector for this pathogen.

In both cases, the tick prefers an undergrowth or high foliage habitat that protects it from the sun. However, it shares this habitat with other species, including one of its predators, the ant.

Ants use an arsenal of chemical signals to coordinate nest defense or food collection. Signals that spiders or bees can recognize to avoid a dangerous encounter. But ticks?

Little was known about it until the study conducted by a team of researchers from Simon Fraser University in Canada, published on Wednesday in the Royal Society Open Science.

They assumed that a common ant species in Canada, Formica oreas, emitted a combination of its usual venom, formic acid, and pheromones marking its territory as an alarm signal.

And a tick could detect these signals, which are very prominent around an ant nest, according to the study.

The researchers tested their hypothesis by placing ticks in a small container with two short tunnels leading to another container, with the paper filter floor neutral on one side and impregnated with ant chemical signals on the other.

The ticks reacted strongly to the combination of venom and pheromones, as well as to their artificial versions. However, the effect of each component taken alone was not conclusive.

The researchers do not rule out that the tick detects other signals emitted by ants, such as those from mandibular glands.