only humans can speak language and other animals can't communicate at all

This statement is not entirely accurate. While it's true that human language is incredibly complex and unique, many animals have their own forms of communication.

1. Animal Communication: Animals use various methods to communicate, including body language, vocalizations, scent marking, and even electrical signals in some species. They convey information about their emotions, intentions, territory, and more.

2. Complex Animal Languages: Some animals have quite sophisticated communication systems. For example:

   • Bees can perform a "waggle dance" to communicate the location of food sources to their hivemates.
   • Dolphins use a variety of clicks, whistles, and body movements to communicate.
   • Elephants can communicate through low-frequency rumbles that can be felt through the ground or heard within their group.

3. Learning New Communication: Some animals, such as dolphins, primates, and certain birds, have been shown to learn and use elements of human languages or artificial communication systems in controlled environments.

4. Limited Compared to Human Language: While animal communication is certainly complex, it's generally less flexible and expressive than human language. Human language allows for abstract thought, complex ideas, and nuanced expression beyond simple needs or emotions.

So, while animal communication is quite different from human language, it's important to recognize that many animals have intricate and meaningful ways of interacting with each other.