I am putting poison down in the stables after the chickens are locked away for the night. A whole plate of 'sachets' disappeared last night so I will put more down tonight.
Those rats probably aren't eating that much poison, the dominant rats are probably taking and hiding the sachets away. As a one time professional pest controller, I don't rate rat poison in sachets at all. There's a lot of wastage with them, because the rats forget where they've stashed them. Its not unusual to find hoards of them in the spring, say when you've gotten to the bottom of the hay or straw store.
I posted this way back in 2006 and have to dig it up fairly regularly. The information contained in it still holds good today. Is it worth making it a sticky? Newbies and oldies might find it useful.
what bodger said about denying them food and a home is vital to reducing them to manageable numbers
a neat trap tip is a bit of string tied to the snapper and just reaching under the box is a good way to know if it is sprung without disturbing a waiting trap.a moved box or human smell will put them off from investigating their doom.
they are neophobic so be patient with trapping,a new trap with fresh bait is much more of a worry than one with old rat ooze etc ,if you can set or rebait wearing mucky gloves do so,if it is too fiddly "farmyard"hands help mask human scent