Turns Out, Donkeys Have a Natural Tick Repellent

A compound found in donkey skin could be the key to keeping ticks—and the diseases they carry—at bay, according to new research from the University of Massachusetts Amherst. Scientists say this natural solution rivals traditional repellents and might offer safer protection for people and pets. People usually rely on chemical tick repellents like DEET and permethrin, but "there is a strong public desire for natural' means of killing and repelling ticks," UMass Amherst microbiologist Stephen Rich tells Phys.org.

The new study published in PLOS One, and co-authored by four high school students who designed and ran key experiments as part of a 2023 summer program, highlights a compound known as (E)-2-octenal, which is secreted by the skin of donkeys. This substance appears to effectively drive away adult deer ticks, the most frequent tick-biting species in the US, known to spread bacterial infections including Lyme disease.

The research team, led by doctoral student Eric Siegel, discovered compounds in donkey skin make their scent unappealing to ticks and that ticks that feed off horses, but not donkeys, are repelled by the compound when it is applied to horses, per MassLive. Specifically, octenal was shown in lab tests to be as good or better than DEET at repelling ticks, and worked particularly well against males. The team is now working to develop a tick repellent for people and pets that takes advantage of this natural compound. (This content was created with the help of AI. Read our AI policy.)