Lions can't purr.
They can roar because they are big animals with no real enemies except humans. They can make all the noise they like - to see off rivals or attract a mate - without having to worry that a bigger animal will hear them and hunt them.
But they can't purr.
So we are superior to lions in purring.
We can purr like a contented universe humming to itself. It's a long low sound that mother cats and kittens make together in the safety of the nest, knowing that quiet hum won't arouse any predators. It's the sound of safety, of happiness, and of love in that blissful nest.
Why can't lions purr? It's a bit of a mystery. It's not just size. Cheetahs can purr, for example: so can snow leopards.
It used to be thought this was something to do with small hyoid bone in the throat and whether it was rigid enough to make a roar but too rigid for a purr. Now scientists have started to argue against this, saying it might be something to do with the folds of the vocal tract.
Purrng is still a wonderful mystery.
We purr without pausing for breath because we purr continuously on the in-breath and on the out-breath. Not many animals can do this.
Humans can't purr. We are their superior in purring.