I have never used the bait boxes posted. I don't worry about secondhand poisoning. A rat eats so little. From my research any predator that eats a poisoned rat is not likely to be poisoned but there may be exceptions. I had a coop that was very infested. I used this bait and rat bait box. The box has a little window above the bait so it can be checked and replaced as needed and only the rats and mice can get to the bait. I did notice some tunnels around the coops and only found a couple of dead rats that I disposed of. I think the others went into their tunnels and died. I'm not crazy about using poison so I place the bait boxes where other critters can't get to them. I tried traps but still had oodles of rats so I resorted to the poison and the bait boxes. I haven't had to replace the baits in quite awhile, nor have I seen any rats. Good luck...

