Fen Traps are like traditional rat traps, but entirely made of steel and about 10 times more powerful than the ordinary trap. Nothing that pokes it's nose into one will survive, once it has gone off. I ordered two of them via eBay, and they arrived in a neat package the day before yesterday. I took them out of the wrapping, and noticed that there didn't seem to be any instructions with them, so I played around with one, trying to work out how to set it by tracing the complex (for me) series of galvanised bars and plates, all controlled by one mighty spring which was situated between the upper and lower assemblies.
I was just gently easing a clip that locked one bar against another (I later found out that this was the safety-catch), when it went off like a gun, trapping three of the fingers on my left hand, but leaving my right hand free to prise the thing open within a matter of two seconds, release my left hand and - whilst still half open - throw it away from me like a grenade, where it hit the ground with a second snap which was a lot louder than the first. It's amazing the strength that you can muster in moments of extreme crisis. Shock and Awe.
The pain prompted me to take a close look at the little finger and - despite a thick, indented ridge in the flesh which stayed for a couple of hours - it was unbroken, and I survived completely unscathed. Not even a bruise.
Now I know Health and Safety practice has got a bit out of hand of late, but can you imagine the mentality of a company which - for the sake of flat-packing convenience - would send these brutish traps through the post ALREADY SET and without instructions????
I have decided that these things are just too unpleasant to use (not to mention that I don't trust my mate to set them away from inquisitive cats), so I won't be giving them to him.