Caterpillars Hear Through Tiny Body Hairs

Tobacco hornworm caterpillars can detect airborne sound using microscopic hairs on their bodies, a new study finds.

Jan. 29, 2026 at 12:31am

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Researchers at Binghamton University have discovered that tobacco hornworm caterpillars, a common garden pest, can actually detect airborne sound through microscopic hairs on their bodies. The study, which was conducted in the university's anechoic chamber, found that the caterpillars are 10 to 100 times more responsive to airborne sound than to surface vibrations felt through their feet.

Why it matters

This research could have implications for improving microphone technology, as scientists look to nature to find better ways to create devices that can detect sound. The findings also provide insight into how these caterpillars may use their ability to hear to detect predatory wasps that could threaten them.

The details

The researchers played low-frequency (150 hertz) and high-frequency (2000 hertz) sounds, measuring how the caterpillars responded to surface vibrations and to the airborne sounds. They found that the caterpillars were far more responsive to the airborne sound. After removing the tiny hairs from the caterpillars' bodies, they were less capable of detecting the sounds, confirming that the hairs are key to their hearing ability.

  • The research was presented at the 6th Joint Meeting of the Acoustical Society of America and the Acoustical Society of Japan in 2026.

The players

Carol Miles

An associate professor of biological sciences at Binghamton University who realized caterpillars could hear after noticing they would jump when she walked into the lab and spoke.

Ronald Miles

A distinguished professor of mechanical engineering at Binghamton University's Thomas J. Watson College of Engineering and Applied Science who has previously researched how other animals respond to sound.

Sara Aghazadeh

A PhD candidate in the Department of Mechanical Engineering at Binghamton University who worked on the caterpillar sound detection research.

Aishwarya Sriram

A PhD candidate in biological sciences at Binghamton University who worked on the caterpillar sound detection research.

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What they’re saying

“Every time I went 'boo' at them, they would jump. And so I just sort of filed it away in the back of my head for many years. Finally, I said, 'Let's find out if they can hear and what they can hear and why.'”

— Carol Miles, Associate Professor of Biological Sciences

“There's an enormous amount of effort and expense on technologies for detecting sound, and there are all kinds of microphones made in this world. We need to learn better ways to create them. And the way it's always been done is to look at what animals do and learn how animals detect sound.”

— Ronald Miles, Distinguished Professor of Mechanical Engineering

“I know this sounds really silly, but there are videos of another species of caterpillar responding to sound on social media. So we knew they responded, but we just didn't know if it was sound or vibration. We were extremely happy when we found out they detect airborne sound as well as base vibration.”

— Aishwarya Sriram, PhD Candidate in Biological Sciences

“A lot of other insects respond to sound, because sound causes motion of the air, and they have little hairs that can respond.”

— Ronald Miles, Distinguished Professor of Mechanical Engineering

“The wing beat frequencies of these predatory wasps are around 150 or 100 to 200 Hz, so I think the caterpillars think that there is a predatory wasp hovering near or above the caterpillar, and that's why it primes itself when it hears the sound, and it reacts with a jump startle, or a freeze, or a twitch response.”

— Aishwarya Sriram, PhD Candidate in Biological Sciences

What’s next

The researchers plan to continue studying how the caterpillars' ability to detect sound through their body hairs may have evolved as a defense mechanism against predatory wasps.

The takeaway

This study not only provides fascinating insights into the sensory capabilities of caterpillars, but also highlights how looking to nature can inspire new innovations in technology, such as improved microphone design.