Ha. I laid out the 'Hensly Palace' as 25x25 run fenced in hardware cloth, buried 2 feet down in a cement trench with the fencing all the way up to the eave of the roof that covers the run. On one side they have an 8x8 hen house. All was blissville until hurricaine Sandy washed out around the cement and it took a few days for me to get it repaired. So the two hens go broody and I come out a few nights into it to check, only to discover, to my horror, half dozen juvie rats that bolt under the house. So the next weekend, I have this lovely portuguese man who helps me in the garden and with the chickens put down hardware cloth all over the floor of the run and seal it in cement around he edges and around the base of the hen house after they put down a bunch of 'just one bite' under the house before they sealed it. 4 days go by. I come out and there are a dozen rats of various ages in various stages of dying in the pen. Good news is they are dead, bad news is they are still getting in right? So now we go on a mission to find where they are coming in. The whole hensly palace is set up about 8' off the back of my garage with a little step that I sit on and commune with my girls and a stone walkway leading to the enclosure. it turns out that the critters were tunneling under the step on the garage, 8' under the walk way, another 25' under the hardware cloth and cement of the run and coming up under the hen house. I have the 5 gallon auto waterer...it turns out, when we pulled up the rubber matting on the floor that they had eaten a hole right under the waterer thru the wood floor about 6" across. We threw more poison in the hole and pored cemet down. Then we screwed down hardware cloth on top of the whole floor, put down another layer of plywood and then relaid the rubber mat. Did I also mention my house is for sale? Nothing like dead vermin..or live ones either....Welcome to my life.
No more rat sightings, but it stinks of the dead ones in the house where the girls are setting.