Hi Glasshopper,
There are thee types of comercially available snail pellets. First type: Methiocarb or other organophosphate (OP). Mode of action: Acetylcholinestesterase inhibitor ie. nerve poison These are the old style. They are by far the most highly effective in killing everything that touches/eats them including (unfortunatly) animals and birds. Definately NOT an organic option... Second type: Metaldehyde. Mode of action:destruction of mucocytes (the cells that enable molluscs to make mucous). this stops them moving and kills them from dehydration. These are also highly effective and they are toxic but unless an animal gets into a packet they are unlikely to cause severe poisoning. Metaldehyde breaks down rapidly in the presence of moisture so in wet areas they don't last too long. I use them as they are the best compromise between a quick kill and environmental friendlyness. Looking on the internet some organic societies think they are organic other only allow thier use in traps and other think they are evil. I guess it depends on your level of fundementalisim. Third type: Iron or copper. Mode of action: asphixiation
These are the new generation of snail 'killers' they rely on the snails eating them rather than just contact. After ingestion the snails eat other stuff until they suffocate. This results in the destruction of a few other seedlings as they don't provide a knockdown action like the first two and the snails crawl away to die in their hidey holes. So you don't get the satisfaction of seeing them dead on the ground. I've used the iron EDTA ones and found they grow fungus a bit to easily for my liking in very wet areas (ie on bog plants). But otherwise they are not toxic and they are highly stable in moisture. Their downside is they must be more delicious then your seedings to be effective. After all that I hope you can make a more informed decision. Regards
Karl, ACT | 
