Answer:
A reaction to being spooked that takes its name from waterfowl
What can stand in place of a country but still fold away in a drawer?
It is by nature, soft as silk; A puffy cloud, white as milk; Snow tops this tropical crop; The dirtiest part of a mop
A hill full, a hole full; yet you cannot catch a bowl full. What is it?
With pointed fangs it sits in wait. With piercing force it doles out fate, over bloodless victims proclaiming its might. Eternally joining in a single bite.
I run through hills. I veer around mountains. I leap over rivers. And crawl through the forests. Step out your door to find me.