Fact 1: Competition may cause animals to fight towards members of their own species.

Fact 2: Competition between male animals is common in nature.

Given the two facts above, answer the question "What is common in males of the same species?" with the following options: 
- competition
 - dancing
 - mating
 - traits
 - females
 - biceps
 - Allergies
 - hormones


 

 competition        