Catnip is a perennial herb from the mint family labiatae. It contains the active ingredient nepetalactone, which is an essential oil that may alter the behaviour of cats. Around 70% of cats will respond to this oil. Kittens younger than 6 months old and before sexual maturity may not react.

A typical response includes sniffing, chewing, licking, followed by face and body rubbing. Some cats may roll their body similar to oestrus pattern. Other behaviours may include stretching, drooling, jumping and hyperactivity. The so called “high” will usually last around 10 minutes.

Wheatgrass on the other hand is just for a cat to chew on. It does not have the effects of changing behaviour.