Fact 1: An animal needs to attract a mate to reproduce.

Fact 2: Animals mate because of smells.

Given the two facts above, answer the question "What do animals use to reproduce?" with the following options: 
- tapeworms
 - glycogen
 - cellulose
 - smells
 - hormones
 - RNA
 - Echinoids
 - pollen


 

    smells     