I reccomend going to TSC and getting the bait I believe its called Rampage it kills them within 12 - 24 hours of ingest... I use the plastic bait shelters to keep kids etc out of them... Rats are one of the worst things you can have on a farm thay carry haunta viris plague etc and eat chickens... You will never win the trap fight for every one you trap there are probably 10 more... Now about 3 - 4 years ago we all of a sudden had a huge rat investation bu the coop I tried the traps finally when I went out and counted 30 one night I pulled out the stops 5 pounds of bait were eaten in like 3 - 4 nites within a week the rats were all gone and I found only one body best thing I ever did... Now I just leave a few blocks out to keep the stray rat away but Ive never had the investation I did...