[ The point of the question seems to sail right over Lucio's head, or maybe he's purposefully obtuse. Either way, it's irritating, as is his assessment. Of course mosquitos and other such bloodsuckers will follow after any warmblooded creature in search of a meal—that's not why he was asking. ]

Only as natural as their prey's instinct to defend themselves. [ He's obviously not going to show any kindness to something that's brought him harm. That said, ] But I don't resent them—you're insinuating feelings where there are none.

[ The truth is, he doesn't care about these bugs a whit besides the bites and markings they leave behind. (He doesn't need to hate something to treat them like nothing—they are nothing.) ]

The real absurdity here is that you'd cradle that thing as it dies. It likely lacks the mental capacity for pain—it may not even be aware of its own existence, much less your sympathy.

[ Where Lucio might see his heartlessness as something flawed, a result of his incomplete heart, Lucilius finds his compassion pointless at best. ]