We have a rat or rats in the attic and it is driving me crazy. We bought our house about 5 years ago and every 6 months or so we seem to get rats in the attic. We've tried everything to get rid of them, traps, peppermint oil, plug in electronic noise things, and poison. Usually the poison gets them after a week or two and we have a few months free before we hear noises again. The house is detached so not coming in through the attic. We have had the council pest control guys out and they can't see any obvious entry points. My assumption therefore is that they are somehow coming from the drains through our foundations and into the cavity wall up to the attic somewhere. Thankfully I've not seen any sign of them outside of the attic but even that is far too close for comfort.
This time they seem to be avoiding the poison and I don't know what else to do. Does anyone have any suggestions for things that actually work to get rid of rats?