Moths have been observed sipping tears from the eyes of a bull moose in Vermont, marking the first such record in a temperate region and expanding our understanding of this unusual behavior beyond the tropics.
Trail camera images captured the event in Green Mountain National Forest, showing at least one moth positioned below the moose’s eyes, with its head along the edge of the eye area. Additional moths flew around the animal, landing on the eyes multiple times over a four-minute period in the early morning hours of June 19, 2024.
The discovery, part of a wildlife survey by the Vermont Fish & Wildlife Department, came from reviewing over 247,000 images of moose across several northeastern states. Researchers identified the behavior as lachryphagy, where butterflies and moths drink tears for minerals or nutrients.
“Lachryphagy is the most plausible explanation,” the researchers state in their study, published in the journal Ecosphere.
Many moths and butterflies feed on flower nectar, but some seek extra nutrients from sources like soil, feces, or even tears. Most reports of tear-drinking come from tropical areas in Africa, Asia, and the Neotropics, where moths visit reptiles, birds, and mammals during dry seasons when nectar is scarce.
This Vermont sighting is only the second record outside the tropics — the first was a moth on a horse in Arkansas in 1972. It involves a wild moose, a new host species, and occurred in a temperate forest environment.
The moths in the images likely belong to the Geometridae family, according to experts consulted by the team. “The moths most likely belong to the family Geometridae (due to size and shape), although the image quality makes it difficult to know their identity with certainty,” say the researchers.
In tropical regions, tear-drinking moths may seek proteins, while in temperate areas like Vermont, they might focus on sodium. The exact reasons in cooler climates remain unclear, but the behavior could relate to supplementing diets in ways similar to gathering at mud puddles.
Large mammals are common hosts for tear-drinking moths, including domestic animals like horses and cattle, and wild ones like elephants in Asia. Among deer species, it has been seen in captive sambar and spotted deer, but this is the first with moose and in a natural setting.
While the event appears rare, researchers speculate on possible effects on moose health. Moths visiting the eyes might transmit diseases like keratoconjunctivitis, which can cause eye lesions. In the eastern U.S., moose already face stresses from parasites such as winter ticks and meningeal worms, and added disease risks could worsen their condition. However, no evidence yet links moths to pathogen spread during tear-feeding.
“The observation of tear-drinking moths in Vermont, United States, substantially expands the known geographic extent of lachryphagy,” the researchers write.
Citations
L. A. Clarfeld et al. Observations of tear-drinking by lepidopterans on moose (Alces americanus americanus) in northeastern North America. Ecosphere. Published online November 20, 2025. DOI: 10.1002/ecs2.70422
