Daddy longlegs are actually bloodthirsty killers—of frogs
May 21, 2026
2 min reading
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Daddy Long Legs Are Actually Bloodthirsty Frog Killers
The wobbly, slender arachnids known as harvestmen or daddy long legs may be overlooked as predators of small vertebrates such as frogs, researchers say.
A kind of Phareicranaus harvester consuming a Pristimantis frog.
Daddy long legs haven’t been considered predators of much, much less vertebrates. But a new study recently published in Ecology and evolution compiled observations showing that lanky arachnids (also called harvestmen) have an appetite for flesh, or at least frog legs.
“We were shocked,” says study co-author Luís Fernando García, an arachnologist at the University of the Republic of Uruguay. “The literature often says that harvesters are omnivorous, that they are slow, that they are weak. »
Some of the first evidence challenging this idea appeared in 2008, when García’s co-author Osvaldo Villarreal, an arachnologist at the Venezuelan Institute for Scientific Research, and other researchers reported that a harvestman was eating a rain frog in a Venezuelan national park. Seeing the photos and videos of a harvester pinning down a troubled frog was “a real moment of awe,” Villarreal said.
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About a decade later, another research team in Brazil encountered a harvestman eating a frog. Then, other co-authors of the new study found that several species of harvestmen preyed on frogs in Ecuador and Colombia between 2020 and 2025. “We found that it might not be so occasional that harvesters might prey on frogs,” says García.
The team compiled known sightings of frog-eating hunters and found that many of these events involved frogs that were still alive, suggesting that daddy long-legs might be hunting rather than scavenging, García says.
It remains unclear how these somewhat unathletic arachnids capture strong, leaping prey, particularly because they lack venom like their spider and scorpion relatives do. Their primarily pinching mouthparts are typically used to nibble on very small insects, fungi and plants, says Jose Valdez of the German Center for Integrative Biodiversity Research, who was not involved in the new paper.
Many tropical harvestman species like those studied are larger and more robust than their temperate relatives, making occasional amphibian feasts more feasible. And the study authors suggest that some species of hunters might rely on their armored exoskeleton and spiny appendages to hold off struggling frogs. But they are relatively little studied.
“There is so much we don’t know about them, even though they are found in many gardens and forests all over the world,” Valdez says.
For García, the results suggest that our understanding of fishermen’s behavior may be biased toward species living in temperate latitudes. In the tropics, food webs are less unidirectional: vertebrates that normally feed on invertebrates such as insects and arachnids can easily find the situation reversed.
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