They're still bugs. Having them inside your house isnt convenient, I can imagine people spraying moths, butterlies and dragonflies if they came inside(dragonflies for the noise alone.) Also they're fairly big insects. I'd personally go for opening a window or door, but I can also understand using a bug killer if they freak you out.(personally butterflies, moths, maybugs and the like freak me out, I hate how the wings move)

Just one question I've had since the beginning. Who uses bug killer on a dragonfly, or a butterfly? I can understand wasps, roaches, misquitoes, even spiders, but dragonflies? Butterflies? I guess there could be some people out there who are that bugphobic. Seriously, I'm probably putting too much though in to this. It is fiction after all. And I do love the story. Besides I like the MC's dragonfly abilities.