I started a thread to track what sort of predators folks are dealing with. Raccoons seem to be the biggest threat to our flocks. https://www.backyardchickens.com/t/261440/the-worst-predator
We haven't (knock on wood) had any racoon sightings (yet) this year. I'v taken out 25-30 in the past 4 years, and I know a couple neighbors (with flocks) have taken out at least that many.