Moles appear to be a real pest in the European. 

 

Moles burrow under lawns and garden beds, sometimes causing the death of vegetation above. Mole controls aren't always very pleasant. For example, tablets containing aluminium phosphide are sometimes placed in mole tunnels where they turn into phosphine gas; poisoning the creatures.

 

Prevention is often better than "cure" and solar power has come to the rescue with a more humane device - the Solar Mole Repeller. The repeller works by emitting a vibrating sound underground every 20-30 seconds to deter moles. 

 

The Solar Mole Repeller produces a penetrating sonic sound of 400Hz over a radius of around 20 metres and an area of approximately 1200 square metres depending on soil type -  a couple of the devices could keep most suburban back yards mole-free. The Solar Mole Repeller is said to also discourage gophers, voles, shrews and other burrowing rodents.

 

One full charge is enough for up to 5 days of power, so the unit can work for extended periods of unfavourable conditions. The Solar Mole Repeller doesn't work instantly however and it may take up to 14 days for it to be fully effective.