After returning from an African research expedition, pathobiology professor Tony Goldberg found an unexpected stowaway: a tick hiding up his right nostril. “When you first realize you have a tick up your nose, it takes a lot of willpower not to claw your face off," Goldberg, a University of Wisconsin–Madison researcher, says in a statement. But Goldberg managed to retrieve the tick from his nostril and send it off for analysis, leading him to not just discover a potentially new species of tick, but what could also be a new explanation for how diseases spread between chimps and humans.

"It takes a lot of willpower not to claw your face off."

Though DNA analysis could only confirm the tick's genus — and not whether it was a new species — because it wasn't fully developed, its presence made Goldberg curious about why it was hiding up there in the first place. Goldberg and other researchers began studying high-resolution photographs of chimps, and they noticed that 20 percent of the chimps had ticks hiding up their nostrils. And that number could be even higher: the photos were far from perfect for studying tick infestations, as they'd been originally taken to examine chimps' teeth. The researchers speculate that additional ticks may simply have been out of sight in the photographs.

The findings were published on September 30th in The American Journal of Tropical Medicine and Hygiene, and focus on chimps and ticks in the Kibale National Park in Uganda. In their paper, Goldberg and others suggest that hiding up nostrils may be an adaptation that these ticks have picked up in order to remain undetected. Chimps frequently groom each other, and by hiding up a nostril, the ticks may be able to feed safely.

But many of these ticks need to feed on three different hosts before they can complete their life cycle, and because they've been found to carry diseases, the researchers suggest these undetected ticks may enable pathogens to spread. "This could be an underappreciated, indirect, and somewhat weird way in which people and chimps share pathogens,” says Goldberg. The researchers note this could allow diseases to spread between animals as well.

"It's not really practical or safe to pick ticks out of chimps' noses."

The researchers haven't been able to capture any additional ticks, and though they might like to, examining chimps directly isn't an option they're currently considering. “It’s not really practical or safe to pick ticks out of chimps’ noses,” Goldberg says in a statement. “The chimps of Kibale are very well habituated to humans, but they would still object vigorously.” The researchers admit that ticks making their way into a human nostril is a rare occurrence, but nonetheless, they suggest there's some risk of international travelers unknowingly helping the ticks set up a population in a foreign country.