Researchers testing a cheap, homegrown oil in Uganda found what cats knew all along – it worked as well as the artificial chemical used globally A homegrown catnip lotion has proven “just as effective as Deet” as a mosquito repellant in trials carried out in Uganda. Catnip, or Nepeta cataria , is a common herb from the mint family. The chemical in the plant that causes feline euphoria – nepetalactone – also has insect-repelling properties but this has not previously been commercialised.