MIKE SWAN says: First things first: remember by law you need to check all traps at least once every day – more if possible. Old timers say you should always put a covering of earth over the plate of a Fenn trap but our experiments prove this isn’t strictly necessary.

What is important is any shiny new trap you might buy should be buried in the ground for several days to remove the gleam and smell of human hands before pressing it into service. Enzymes in the soil will help do this.

Some old keepers we meet reckon the best place to bury them is in an old muck heap where the tarnishing process is speeded up. Vermin will steer clear of traps which smell of humans, so, when checking your Fenns each day, make sure to wear gloves.

‘Weathering’ traps in this way will certainly improve your catch rate if the tunnels are properly sited in the first place. But a word of warning, the effectiveness of any trapping campaign will be reduced if your traps can be seen by passing members of the public, folk who do not understand the importance of trapping vermin, and what you are trying to do.

The only practical thing you can do is make sure the tunnel traps are well hidden from passers-by. Either make sure they are camouflaged from prying eyes, or put them in places where walkers can’t see them. In other words, set them away from public footpaths.

Got a question? Contact: or Sporting Gun, PO Box 157, Stamford, Lincolnshire PE9 9FU