Fact 1: Sound can be used for communication by animals.

Fact 2: Many animals rely on sounds to communicate to others in their species.

Given the two facts above, answer the question "What do species rely on to talk?" with the following options: 
- Frogs
 - energy
 - language
 - hands
 - squids
 - feet
 - Frogs.
 - sound


 

        sound 