Neuroscientists at Northwestern University have made an amazing discovery about catnip, it repels mosquitoes and other insects. The active component of catnip (Nepeta catoria) is nepetalactone which stimulates a neuroreceptor called TRPA1. TRPA1 is found in most animals from insects to humans, and transmits pain sensation to the brain. TRPA1 can also be triggered by hot, cold, and irritants.
The interesting thing is that when applied to humans as a repellant it does not trigger a pain response in the human, nor does it trigger pain in felines. In felines it triggers a different receptor involved in pleasure sensation.
Work is underway to find an effective way to use nepetalactone in an easily applied skin vehicle to provide a non-DEET alternative for summer misery.