[jstarfish]

This is what we're told but "because pests" is a bit ambiguous.

Ever had rats? Fuckers will climb literally anything and get into literally everything. "Roof rats" are a thing.

Elevation does not deter any pest I'm aware of (bears maybe). Your bed will get bedbugs same as a futon, but in the case of rodents their droppings always fall downward. Keeping stuff off the ground keeps it away from filth.