Cats like catnip because it contains a compound called nepetalactone that triggers a euphoric or happy reaction in many cats. When cats sniff or rub against catnip, nepetalactone binds to receptors in their nasal tissue and stimulates brain areas linked to emotion and behavior, causing reactions such as rolling, rubbing, purring, hyperactivity, or calm relaxation. Scientists believe the effect may be because nepetalactone mimics cat pheromones, which leads to the cats experiencing a natural mood-enhancing or euphoric feeling. The effects typically last about 10 to 15 minutes, after which cats become temporarily immune to catnip's effects for a while. About 30% of cats do not respond to catnip, as sensitivity is genetic. The effect is safe and non- addictive, and can vary from hyperactive play to calm contentment depending on the cat.