So briefly looked at the video of SWISSINNO [...] and losgelegt. In winter, the mice dig deeper, which is probably related to the cold. The course then fall steeply and man should not be too far from the hole set the trap, otherwise extends the maximum depth of 14cm is errreicht quickly.
So I made sure that holes are more frequented (you can see the lack of grass or on the flat way past Earth) and this, equipped with traps, as explained in the video. Within the first hour two voles have been caught. I've emptied the traps and inserted into the same holes again. Overnight all of my four cases had triggered and in each there was a dead vole. Within the next 24 hours were still two to tango. As the next two days was carried out not only catch more, I put the traps into a new area and also here fast successes.
The traps should be cleaned after each catch with hot water without additives with a bottle brush, so the smell of the dead mouse does not scare other mice. Also the lower part of the case should not be touched.
Conclusion: I like the easy handling and the quick kill the mouse. The only drawback (no star trigger value) is the me of a trigger event has been gnawed by a field mouse, since it consists only of plastic. Have replaced it with wire and it works as before.