You are presented with the question "What crawls and is known to have a complex nervous system? " and the following answer choices: 
- fur seals
 - Insects.
 - mammals
 - animals
 - a fish
 - humans
 - bees
 - ducks

Now knowing that most invertebrates have a more complex nervous system and insects are the most common invertebrates, choose the best answer.


 

  Insects.       