As you can see from the farming forum UK, there is quite a bit of discussion about the the Goodnature traps. Especially around the replacement of poison.
I have added to the comments to stating that I believe that most farmers at heart are environmentalists. The Goodnature traps go along way into helping reduce poison use around farms. I would welcome any attempt, with any trap that does this. However I believe the goodnature traps are the most cost effective and humane.
The thread of the conversation can be found here: