If anyone decides to use the blue pellets don't use too many, four or five to a square yard should be enough, the slugs will find them. I often see small piles of them in gardens, when they're put down like that they're more likely to attract the attention of cats, who will eat them and have fits. On the whole dogs don't seem as stupid. I don't like using pellets so I would opt to go out and pick them up. It's argued that slug trails contain all sorts of different chemicals, from substances that mark the direction of travel, to ones that slow the growth rate of smaller slugs so preventing over-crowding. The greenest answer to slugs is to grow plants that they won't eat, the same way the best answer to blackspot, rust and everything else on roses is choose varieties that are resistant.