How big of an explosion do you think a drone small enough to fly through your ear canal is really going to be? How does it even reach its target with such a minuscule mass? The target exhaling would blow it away (and likely destroy it)
Obviously it would require enough to blow out your brains to be effect. How do you propose to create a drone so tiny and light to also carry the payload required to do that? Just because the payload itself could fit into someones ear doesn't mean the delivery mechanism can, well, actually deliver it
