Locust Brains Can Surprisingly Detect Dangerous Forever Chemicals In The Environment

Scientists have identified an unlikely ally in the fight against environmental pollution: the locust. New research reveals that these insects possess a specialized neural response capable of identifying various per- and polyfluoroalkyl substances (PFAS), commonly known as “forever chemicals,” even at trace levels found in the wild.

PFAS are ubiquitous in modern manufacturing, integrated into everything from nonstick surfaces and water-repellent textiles to specialized firefighting foams. Their durability, which makes them so useful for industry, also ensures they persist indefinitely in soil, water, and biological tissues. This environmental persistence has created an urgent, global need for more effective, field-ready monitoring technologies.

Debajit Saha, an associate professor at Michigan State University’s College of Engineering and Institute for Quantitative Health Science and Engineering, emphasizes the technical difficulty of the current crisis. “PFAS are extremely difficult to detect,” Saha stated. “There is a tremendous need for technologies that can identify them at very low concentrations.”

While human-engineered sensors often struggle to match the precision of natural biological systems, insects have long evolved sophisticated olfactory pathways to navigate their surroundings. To determine if this biological sensitivity could be leveraged for environmental monitoring, researchers monitored the brain activity of locusts as they were exposed to airborne PFAS compounds, including the highly regulated and pervasive PFOS.

The results, published in the Journal of Hazardous Materials Advances, suggest that the insect brain reacts with remarkable specificity. Each individual PFAS compound triggered a unique neural signature, or “odor fingerprint,” enabling the locusts to distinguish between different chemical structures. Summer McLane-Svoboda, the study’s lead author and a doctoral candidate in the Saha lab, noted that the team was initially uncertain if any reaction would occur. “Once we saw distinct neural patterns for different compounds, we realized biology could become a powerful PFAS-sensing platform,” she explained.

The discovery presents a biological mystery. Because PFAS are strictly synthetic, they do not exist in nature, meaning insects have not had millions of years to evolve specific sensors for them. Yet, the locust brain displays a robust, sensitive reaction to these man-made chemicals. “For some reason, the insect’s sensory system is able to detect these human-made chemicals, even though they don’t naturally occur in the environment,” Saha observed.

Currently, the gold standard for PFAS detection relies on liquid chromatography-mass spectrometry. While these laboratory methods are precise, they are also bulky, expensive, and require significant infrastructure, making them impractical for rapid, onsite environmental testing. The researchers view this new finding as a critical proof of concept that could bridge that gap.

The research team is already pivoting toward real-world applications, currently testing the locusts’ efficacy on water samples gathered from various sites across Michigan. Their long-term goal is to translate these biological insights into portable, miniaturized sensor technology. By harnessing the natural sensing capabilities of the locust, scientists hope to develop a faster, more versatile diagnostic tool for identifying and managing chemical contamination in the field.