Genetics

You may have noticed that not every cat falls prey to the temptations of catnip. In fact, only about one in two cats is attracted to catnip. Genetics determine this -- so if you have a playful cat who loves the substance, it might have to do with her genes. In fact, it's not only domestic cats that are drawn to the herb -- it is also wildcats, such as lions, tigers and panthers.

Age

Attraction to catnip is something that becomes evident as cats grow up. The first time you might see a reaction in your feline might not be until he is 3 to 6 months of age. By the same token, senior cats might not respond with the same vigor as they once did when they were middle-aged, demonstrating less of the playfulness that catnip can invoke.

Scent

Cats are scent-driven creatures. Their hunting instincts and everyday communication is based on what they sense in the air, through their noses and scent glands. Catnip is a plant whose smell is strong, at least to felines. The herb's intoxicating properties are therefore transmitted to the cat through the vehicle she uses to interact with the world: her sense of smell.

Nepetalactone

Catnip contains an oil that is attractive to kitty cats -- nepetalactone. According to Animal Planet, it is this oil that triggers a response in a cat's brain that leads to the distinctive behavior -- licking, chewing and rolling around. Catnip sprays contain less of this oil than do the dried or fresh herb versions of the plant -- for this reason sprays tend to invoke less of a reaction.

Timing

You might notice your kitty's reaction to catnip is short-lived. In fact, the catnip euphoria lasts just a few minutes -- and then your cat probably will lose interest. An hour or two later, however, she'll be back again, ready for another playful romp. This is a natural phenomenon -- your cat will be catnip-happy for awhile, then will need a break before her brain is susceptible again to its temptations.