Do hamsters defecate when they're scared?

Answer 1

Sometimes, yes, all animals including hamsters will defecate when scared. The "fight or flight" instinct in animals when they are frightened can sometimes wreak havoc on the central nervous system and can make animals lose control over bodily functions.

Answer 2

They can. they normally like peace and quiet, and if they get lots of it, they won't get scared and stink up the place.