When we go to sleep, they start to appear. The luminous fireflies look for a partner, the beech marten crawls out of the attic, the racoon climbs out of the chimney, his sleeping place during the day. These nocturnal animals live in our close neighbourhood because here they find abundant food. However, they also cause us sleepless nights. Fat dormice explore noisily our apartments, and martens nibble on the cables in our cars. They don’t need any artificial lights, which brighten our nights, because they even endanger their own lives!