Researcher stunned by unprecedented footage of extremely rare behavior in US region: 'Looked like … two [additional] eyes'

Generate Key Takeaways

A scientist in New England came across startling images captured by a trail camera, showing the first documented case of this strange insect behavior in the region.

What's happening?

"It almost looked like the moose had two [additional] eyes," Laurence Clarfeld, an environmental researcher at the University of Vermont, told Scientific American. "At first, I wasn't sure what it was."

Clarfeld was describing a scene in which moths could be seen feeding on moose tears. He'd come across the surprising moment while reviewing footage from a camera trap in the Green Mountain National Forest.

Advertisement
Advertisement
Advertisement
Advertisement

The thirsty bugs weren't indulging in schadenfreude, but in lachryphagy, or "tear eating," a process by which moths and other insects sup on the tears of larger animals — even humans.

And yet, it's not the act itself that's remarkable, but where it happened. Lachryphagy has long been assumed to occur almost exclusively in tropical climates. Observing this behavior in Vermont confounds the still-quite-limited scholarly understanding of it.

According to Scientific American, there is only one other known and documented case of lachryphagy outside the tropics. That instance took place in Arkansas.

So what is it about tears that bugs find so enticing? There's no definitive answer yet, but one possible explanation is the unusually high protein content of tears, which is 200 times that of sweat.

Why is this concerning?

One of the biggest risks of lachryphagy comes from its potential to spread disease. Clarfeld and two co-authors published an article on the footage in Ecosphere in November. They posited that "eye-visiting moths may be vectors for disease transmission such as keratoconjunctivitis, a condition that may induce eye lesions in moose, with significant health impacts."

Advertisement
Advertisement
Advertisement
Advertisement

Moose are already at risk of afflictions like chronic wasting disease, so they hardly need another source of infection. Moreover, the dangers could heighten as rising global temperatures expand the travel ranges of disease vectors.

What's being done to better understand lachryphagy?

There's still a great deal to be learned about lachryphagy, especially now that it has been observed in an entirely new type of climate. For scientists, the chance discovery is a call for further research and awareness.

It's also a reminder of why trail cameras are some of the most powerful tools in wildlife research. A well-placed camera can reveal enormously valuable information about the population and status of a species in an area.

As in this case, cameras can also uncover previously unknown behaviors that could further our understanding of nature.

Get TCD's free newsletters for easy tips to save more, waste less, and make smarter choices — and earn up to $5,000 toward clean upgrades in TCD's exclusive Rewards Club.

• About Our Ads