Imagine being a spider, walking across the floor.. maybe looking for a place to put your home? chillin out, tryin to find some flies. next thing you know this creature 1000x bigger than you walks in, sees you, screams and runs for vacuum/shoe/tissue and crushes your body until your organs and insides are squeezed out of your tiny body. A couple legs ripped in half, the others broken and tangled. Then you're thrown into a garbage to sit there and rot, or flushed down the toilet into the ocean. A very traumatic experience, from an idiomatic point of view.