Garter snakes eat more than bugs, they eat mice too.
There were lots of Garter snakes around my grandmother's house. As a child I played with them. Now I prefer to see them first and it has been a few years since I picked on up. I think being startled is normal when something moves unexpectedly.
I once saw a writhing mass of mating snakes, it was about the size of a basket ball. Fascinating.
The only times we have had a snake inside is when the cats brought them in. We have had many cats that like to play with snakes, but none that killed them.
My step mum is from NZ where they have no snakes. She lives in my grandmother's house for 4-5 months of each year, the summer when the snakes are out. She has gotten used to them, thank goodness her heart is strong.