Yes, cats can eat catnip. Eating catnip generally produces a calming or sedative effect in cats, which is different from the stimulating reaction many cats exhibit when they smell it. Catnip is safe for cats and non-addictive, though eating too much can sometimes cause mild gastrointestinal upset such as nausea or diarrhea. Some cats may not react to catnip at all due to genetic factors, and kittens under one year typically do not respond to it. Pregnant or nursing cats, cats with neurological problems, or those prone to aggression should avoid catnip to prevent adverse reactions. Overall, catnip is a safe, natural treat that many cats enjoy either by smelling or eating it, but it is best given in moderation and under supervision initially.