Originally posted by JPValheim:

Aww man I'm sorry, what unlucky timing with the bat raid. I've played for 1000+ hours and never even seen the bat event. RNG at its finest huh?

Unfortauntely, once you kill your first bat, and bonemass, the bat event becomes possible which changes how you must protect your animals. Your boar and chickens will be vulnerable from now on unless they are inside of a building. So, to protect them, they must be totally enclosed. No windows. No open sky. Nothing.

Or never kill a bat. If you never kill a bat in the caves; you'll never get the bat event. They aren't necessary to fight so its entirely possible to avoid them

I don't know about the not killing a bat. I watched a YouTube video on the raids and they indicated if it gets killed in that particular world you are in they will raid. Even if you don't kill them.