Catnip is a perennial herb, which means it grows through more than one growing season, and it contains an ingredient called nepetalactone. It is this naturally occurring chemical that kittens and cats react to by becoming more active, purring, and rolling, or even licking and drooling — some may eat the catnip as well. This is generally safe, as catnip isn't toxic. It is generally considered safe to use catnip for kittens, but it is important to note that some cats may not prove very interested in the herb, especially kittens that are younger than two to three months old and some elderly cats.
Often, people question whether it is safe to use catnip for kittens for a couple of reasons. First, they may question whether a kitten's system will prove more vulnerable to something harmful that could be in the catnip. Second, they may wonder whether any ingredients in the catnip could be generally harmful. The good news is, catnip is non-toxic to cats of any age, including kittens.
One thing that is important to note about using catnip for kittens is that some may attempt to eat it in addition to just sniffing it or playing with it inside of a pet toy. Eating a small amount of catnip is unlikely to cause a cat any harm. If the cat eats it in extremely large amounts, however, he may vomit or develop diarrhea. Still, it is unlikely to cause any serious or lasting effects when it is ingested.
Scientists believe that the chemical nepetalactone is responsible for the cats' favorable responses to catnip, as it produces the same sort of reactions as sex pheromones in cats and kittens. The reactions, however, may vary from kitten to kitten. Some may seemed lulled by it while others become very excited and frisky. Many cats like to rub or roll over catnip or an item containing it, and paw or claw at it. Additionally, some become very jumpy and playful in its presence, and many lick, sniff, and nibble on it as well.
Despite the fact that using catnip for kittens is considered safe, it is important to note that some cats may not seem as interested in it as others. For example, kittens who are younger than about two to three months old are often disinterested in it. Likewise, elderly cats may not seem as interested as younger cats.