We\u2019ve all heard of snail mail \u2013 a term popularised since the advent of electronic mail \u2013 but who knew that snails eat mail?<\/p>\n
We have it on good authority from the ecologist Simon Mustoe \u2013 who said snails ate his letter from Sir David Attenborough<\/a> \u2013 a BBC report announcing the closure of a Northumberland Royal Mail postbox<\/a> because of snails \u201cmunching the mail\u201d, and desperate people on the forums of the Australian hardware chain Bunnings<\/a> claiming snails have \u201ca real appetite for postal letters\u201d and can \u201ceat a whole letter in two days\u201d.<\/p>\n This didn\u2019t escape the comedian Jimeoin<\/a>, who joked after moving to Australia that he had found a snail eating his mail and said to it: \u201cYou stupid snail, you\u2019re supposed to eat lettuce, not letters.\u201d<\/p>\n Dr John Stanisic, AKA the Snail Whisperer<\/a>, says letters are processed vegetable matter so it makes sense that snails have an appetite for them \u2013 and not just for mail. Preparing for a two-day photoshoot for the Australian science program Catalyst \u201csome years back\u201d, Stanisic set up some snails in a Chinese takeaway food container and got a rude shock the next day: \u201cSomehow, through the night, they got out and they\u2019d eaten the front page of my running sheet.\u201d<\/p>\n Exploring this is like following Alice into a virtual wonderland of these ancient gastropod molluscs \u2013 which include the eye-catching Mount Kaputar pink slug, the giant African snail, which can grow to the length of an adult human\u2019s forearm, and the golden-haired snail \u2013 that harks back 350m years.<\/p>\n Mustoe, the author of Wildlife in the Balance and How to Survive the Next 100 Years: Lessons from Nature, explains that snails, one of the oldest known animal groups, consume waste, which is critical for ecosystems. So, he reasons, they could have helped prevent the late Devonian mass extinction that was caused by a surge in plant evolution and not enough animals to eat them.<\/p>\n A partially eaten letter from Sir David Attenborough. Photograph: Simon Mustoe<\/p>\n Dr Isabel Hyman, a snail and slug enthusiast from the Australian Museum<\/a>, says: \u201cThey\u2019re very important in terms of their position in the food web. People tend to have a stronger connection to the idea of the mammals and birds \u2026 but those things need a flourishing ecosystem, which needs all the little invertebrates<\/a>.\u201d<\/p>\n Stanisic, who authored A Guide to Land Snails of Australia and is an honorary research fellow at the Queensland Museum, says Australia has about 2,500 native species, with exotic names including the rosy wolf snail, the red triangle slug and the leopard slug. He thinks they are fascinating. \u201cPeople seem to think a good snail is a dead snail, but I\u2019ve come to realise that snails are a very complex animal in their behaviour and they\u2019ve really got everything down to a T.\u201d<\/p>\n Australian native snails don\u2019t do well in disturbed habitats. It is the common garden variety, introduced from Europe 120 years ago, that appear to be the letter-munching culprits. They are most likely to seek refuge in letterboxes in humid conditions and a ready source of food is a bonus. Moisture is a matter of survival for snails, Stanisic explains, which they need to create two types of mucus: one they exude from cells under their \u201cchin\u201d to create slime trails to walk on. \u201cThe other is this slime network over their entire body, which just pumps out moisture all the time to keep the snails active.\u201d<\/p>\n Hungry snails in Simon Mustoe\u2019s mailbox Photograph: Simon Mustoe<\/p>\n Hyman concedes that in Australia common garden snails can be considered pests \u2013 \u201cthat give a really bad rap to all the native species\u201d \u2013 but urges a mindful approach to controlling them. \u201cI have no compunction in feeding them to blue tongue lizards or something like that. What we don\u2019t want to do though is introduce poisons that might also be impacting our native invertebrates.\u201d<\/p>\n Blue tongue lizard populations are collapsing in urban areas because of these poisons, according to Mustoe. Snail pellets can kill their natural predators, which in Australia include birds, mammals, insects, toads, turtles and wild turkeys. Snail pellets can also kill pets \u2013 personally I know someone whose French bulldog found a packet, munched on them and died.<\/p>\n How do we stop them eating our mail without hurting innocent bystanders? Hyman recommends a two-pronged approach. First, copper tape provides an effective barrier by creating an uncomfortable electric charge when the snail\u2019s mucus contacts the metal. This can be combined with creating a sharp angle, which they don\u2019t like crawling over.<\/p>\n