Animals also can communicate. Some animals and birds like dog, dolphins, gibbons, herring gulls and honey bees have developed their own system of communication. But their communication system differs from human communication. Animal communication lacks flexibility and creativity. Their communication tradition is acquired genetically and not through learning.
Human language has got certain properties which makes it unique and different from animal communication system. These properties are duality, creativity, displacement, arbitrariness, interchangeability etc.