system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why does flicking a small insect not kill it? Is the force not as strong as squishing it?

Same thing with swatting them out of the sky. 

Does it have to do with surface area? Do their bodies have structures to resist immediate strong impacts, but fail against sustained moderate forces?
gpt
It's mostly to do with mass. The less mass an object has, the easier it is to accelerate (so more energy goes to actual movement, and less to the object deforming.)
Insects have very little mass, so they don't experience much resistance to acceleration (the flick.)

Alternatively, squishing against a hard surface results in most of the energy being used to actually deform the insect, as it doesn't have anywhere to accelerate to.