Scientists may have finally found how catnip repels insects.
The active component of catnip (Nepeta cataria) repels insects. It does this by triggering a chemical receptor that can spur sensations such as pain or itch. Researchers reported this March 4 in Current Biology. The sensor is dubbed TRPA1. It is common in animals – from flatworms to people. And it’s what triggers a person to cough or an insect to flee when they encounter an irritant. Those irritants can range from cold or heat to wasabi or tear gas.
Catnip’s repellent effect on insects — and its effect of excitement and joy in felines — are well documented. Studies have shown that catnip may be as effective at deterring insects as the widely used synthetic repellent diethyl-m-toluamide. That chemical is better known as DEET. What hadn’t been known was how catnip repelled insects.

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