(CW: animal death) Anyone have any experience with rat infestations in homeless encampments?

One near me is having an issue with rats. I think really they just need better trash pickup mainly, and better shelters in general, but they've specifically asked for help getting rat poison. Would bait boxes with poison even make a dent in an outdoor environment like that? I can't singlehandedly improve the cleanliness of the camp or get everyone rat-proof shelter obviously, but I feel like just going straight for the poison could have adverse consequences and not be effective, potentially.