Please, please, please don't use slug pellets. We are loosing our blackbirds, thrushes, frogs and hedgehogs being poisoned by the pellets when they eat the slugs and snails! I know that they are a damn nuisance, but there are other ways to kill em off. Sprinkle salt on them; put them in boiling water; set beer traps; slice them in half lengthways (they can reproduce if cut across the body), anything but not the pellets.
If you have any vunerable plants in posts i.e Hosta the Slug Stoppa Tape (made by Fito) is excellent. I have this around two planters in my garden and the leaves are untouched, and have been since I first used the tape 4 years ago. Apparently the copper tape gives the slugs or snails a mild electric type shock.