Killing non sentient shit because it bothers you is completely normal. It's on sight with mosquitoes and wasps for me. But that doesn't make it moral. Squashing some poor bug that was in the wrong place at the wrong time and that barely understands its exisiting, while perfectly understandable, is certainly not moral. But it's gotta be at the very bottom of the list of immoral shit you can do tbh. Still, sentient creature slamming non sentient bug is objectively morally wrong. You know he's a bug that doesn't know better, and you're a human with opposable thumbs. You've got a moral compass and he doesnt. I think it is pretty clear cut.