Fun fact: Giant water bugs are also called "toe biters" because they often hang out at the bottom of fresh water ponds and lakes and love to bite the feet of unsuspecting big dumb humans who wade into their pools. Belostomatidae have huge mandibles (I can attest to this, having seen one close up first hand) and (according to Wikipedia) "their bite is considered one of the most painful that can be inflicted by any insect, however, though excruciatingly painful, it is of no medical significance."
Not medically significant. That's nice.
You want to know the best thing about these bastards? The absolute best thing?