The GARDENA gardening expert
Dear Mr. W., as you know, moles are protected under nature conservation laws, meaning that you cannot put down killing traps for them. However, you are allowed to drive them off. There are many different systems for doing this, for example by generating particular sounds. Experience has shown that the success of such methods differs; some people are certain of their efficacy, whilst others have had little or no success with them. This is also the case for so-called denaturants, which work using fragrances.
However, what are quite successful amongst these agents are the Mole-Stop (Maulwurf-Stopp) or Mole-Scare (Maulwurf-Schreck) (both manufactured by Neudorff). These work using special citrus aromas. Moles definitely do not like this aroma.