Many kittens, and some adult cats, aren’t much interested in catnip.
Some dogs are, though.
There’s a lot of Cat that humans can’t speak, because it’s said with the tail (which we haven’t got at all), or with the ears (which we don’t have enough outer parts of to move properly), or even by raising the fur. But we can learn to understand quite a bit of it.
And some of it we can speak. I gave an example a bit upthread.
Dogs usually try to learn Human. But cats expect the humans to learn Cat.