You say that animals don't have language. But I am not convinced. Perhaps some animals, or even most animals, don't have language. But whalesong and bird song

You say that animals don't have language. But I am not convinced. Perhaps some animals, or even most animals, don't have language. But whalesong and bird songs can be very complex, and I am not at all convinced that they do not have language. Can you prove that they don't have language?