Cats only meow at each other as kittens; adult cats only meow at humans. That’s because they’ve learned that we respond to it. Cats meow when they’re hungry, need to go out, want your attention, or just want to say hello. Older cats or cats with mental disorders may also meow for no apparent reason. In general, though, they’re meowing to let you know something, even if you can’t always figure it out. Cats do yowl at each other – a long, extended form of meow – during mating or fighting.