Random Ravager spawning

I and a few friends own a realm on which we build a world in survival. Lately, however, it has often happened that a Ravager is spawned in the bases of players. Since this happened by accident, and no raid was started and several Ravagers were spawned at the same time, I ask you to take a look at the problem, because it is really annoying when Ravager spawns simply. I would appreciate a feedback!