Total and utter goodies - they eat slugs. Love and nurture them. They are shy and like the cool so provide them with some shelter. If you use slug traps, leave a 1-2cm lip because they are rubbish climbers. If you have a massive slug problem in one area , you can lower the soil level in that area by 2-3 cms, they fall in, can't climb out and feast on the slugs.