Fact 1: Migration is a type of movement that changes population size.

Fact 2: Population viability Population sizes are under constant fluctuation.

Given the two facts above, answer the question "What can happen to a population when animals begin to migrate?" with the following options: 
- It expands
 - harm them
 - it can change species
 - Move to another area
 - it can eat more
 - it can go extinct
 - it can fluctuate
 - Plant growth is reduced


 

       it can fluctuate  