What other poison baits did you use besides Tomcat? I had to use multiple poisons as mentioned.
I set out the bait stations and loaded up PCV pipes around the pens with poison.
Here, it was flooding rains last summer that brought them to higher ground (my pens.) Try the ammonia soaked rags, they work. They havnt returned, but I'm ready for them if they do. The bait stations and PVC pipes have poison waiting for them to return. If there are rodent holes around your pens, stuff a poison cylinder bait down the hole and cover it with a paver, like in the first pic below.
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