Fact 1: Loud noises can cause animals to startle.

Fact 2: All animals are startled by an unannounced approach, a sudden movement, or a loud noise.

Given the two facts above, answer the question "what can animals be startled by?" with the following options: 
- murmur
 - reflexes
 - vehicles
 - movement
 - rain
 - photons
 - waves
 - an object


 

    movement     