Oat bran update: bought some oat bran yesterday and sprinkled some on a paving slab in the garden - checked back after midnight with a torch and there were several feasting on it - so it definately attracts them. Woke up late this morning and it was raining heavily so all the oat bran had dissaapeared and so had the slugs! Don't know if the oat bran killed them and the birds ate them earlier or if they crawled away to die? Will try again tonight if it's dry...