Many thanks for the replies, and also for the very informative link.
The subject of Desert animals consuming snails was something I was going to ask about later. Monitor Lizards are my main area of interest, and whilst location information is unavailable for the parent stock of Australian species, among those that I keep there are species which at the very least come from more arid environs and I have never had any problem getting them to accept Snails. There are a number of more specialised Snail species which do live in desert areas, but I don't think that these are widely available, they might be worth trying if you could find a source.
Kindest regards,
Alex