Fact 1: Harming an animal species has a negative impact on the population size of that species.

Fact 2: Hot weather can cause harmful bacterial growth in feeders.

Given the two facts above, answer the question "What can have a negative impact on a species' population size?" with the following options: 
- cigarettes
 - Pesticides
 - steroids
 - humans
 - weather
 - flooding
 - Smoking
 - viruses


 

     weather    