Catnip is the common name given both to the chemical that attracts cats and the plant it comes from. The Latin name for the plant is Nepatia cataria and the proper name for the chemical that some cats love is nepetalactone. Catnip isn't just used to send cats wild, it is also
part of human herbal medicine in the form of teas and tablets.(Before you rush out to buy
some, it doesn't have the same effect on people as it does on cats!)
Catnip is a funny chemical because it is detected not in the nose but in the 'vomeronasal organ'. This is a primitive chemical detector in the roof of the mouth that only responds to certain chemicals. Snakes depend upon this organ for most of their sense of 'smell' but in most other animals it only detects a very small number of things.
When cats sniff catnip it seems to produce total joy and abandonment for up to 6 minutes, with rolling and cavorting about. I believe that research has been carried out with this chemical in big cats like lions with similar results! Many toy manufacturers use catnip to attract cats to play because some of them like it so much.
As you have noticed, a lot of cats do not respond to catnip at all. It works best on normal adult cats, but as they become older they lose interest. Kittens also don't take any interest. Even among normal adult cats about 50% are not affected by catnip because they lack certain genes that cause the catnip reaction.
It sounds as though your other two cats fit into one of these groups. Don't worry, cats don't need catnip, and not liking it doesn't mean your cat is at a disadvantage in any other way.
Jon Bowen, vet and behaviour expert
CATS TODAY Dec/Jan 2001