It is disclosed a device comprising a threshold listing or cloth for preventing the passage of pests and vermin into a geographical area or building, wherein said device comprises a horizontally running listing (1) or cloth, wherein said listing or 5 cloth (1) on its surface comprises a number of electrically non-insulated rails or wires (2,2',2"), conducting electrical current and wherein said rails or wires will short-circuit when touched. It is also disclosed a system comprising photosensors or other type of sensor (7,8,9) where activation thereof will switch off the current to the electrically non-insulated wires or rails (2,2',2") so that animals and humans 10 of a selected size may touch the device without experiencing an electrical jolt.
