What crawls and is known to have a complex nervous system? 
fur seals Insects. mammals animals a fish humans bees ducks
A B C D E F G H
Insects are the most common invertebrates.
Insects have a more complex nervous system.
What crawls and is known to have a complex nervous system?  (A) fur seals (B) Insects. (C) mammals (D) animals (E) a fish (F) humans (G) bees (H) ducks