system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does cat nip effect cats like it does, but not dogs or other animals?

Thanks for the help, I've always been curious.
gpt
Terms to know:
Nepetalactone - a compound in catnip
/ Olfactory system - the sensory system used for smell

In short, researchers are really unsure what exactly causes the cats to go into a craze like they do, thus they can't figure out why dogs / other animals aren't so easily affected by it. There isn't really an answer to this, however, here's a little information on what happens. 

From what researchers can grasp onto.. Inside of catnip there is nepetalactone, which is known to be a very strong compound. The way that this compound effects cats is that it gets into the cats noses and to where the olfactory system is, the nepetalactone binds to the receptors inside of the olfactory system and triggers signals to the brain. Researchers aren't quite sure why exactly cats react to it as they do, they suspect that it pretty much mimics cats "happy" pheromones and cause a reaction in their brains that is the same reaction that comes from those "happy" pheromones. 

For measure on how strong catnip is-- researchers say that the compound nepetalactone is up to TEN times more effective at repelling insects than the most commonly used compound in insect repellents. So imagine all that strength inside of the cats little nosies? Crazy, right?