Luck, or mouse depending

I have gained this device after a vole began to plow our land. Unfortunately, it was unsuccessful. Shortly after inserting the device was close to it, a new mound of dirt to be seen. I then tried the device at different places to find an optimum location (several months). Without Success. Meanwhile, I think it is a matter of luck, to expel a vole with "noise". Wühlmaushaufen right on the rail line or highway. If that does not even abschrekt ...

About the unit itself, I can not complain. It makes a solid impression and is well made. The failure is not due in my opinion on this particular machine, but rather "mouse-dependent". It may well be that there are noise-sensitive voles, our in any case seems to feel attracted to the device to feel ...