Is your cat getting high on cat nip? Why is this? What makes a cat go crazy over cat nip? It’s because of the plant’s natural chemical, trans-nepetalactone. It’s the smell rather than the taste that drives cats wild. This is similar to the essence excreted by females cats which male cats really love.  Females also love this scent. Kittens usually don’t respond to cat nip until they are about two months old. So instead of buying your cat a cat toy, try something that will make her feels like she’s in heaven – cat nip.