Hey,
I get raids from ladybugs and mosquitoes and I don't kill them, unless they attack me on my travels, or I need materials from them. For materials, I only kill the required amount of bugs to craft the armor or weapon. I think that after a while a raid will occur regardless if you kill bugs in large numbers or not. This is what happens to me in my game, and I don't like it one bit. I can handle the Mosquitoes, but Ladybugs and their variants wreck my base in no time. Being able to turn off the Faction raids would take nothing away from other players.
Greetings