I’ve a small corrugated shed, connected to the house, which is constructed around two trees: a large self-seeded cherry and an old, gnarled elderflower. A space carved out of the corrugated roof allows their trunks to pierce through, but the openings around them weren’t properly waterproofed, so whenever it rains, water seeps through the gaps, soaking the trunks inside and leaving darkened streaks as the trees absorb the moisture.
A damp, soggy shed is frustratingly impractical, but it has attracted visitors. A series of shimmering trails across the tree trunks, stretching out along the wooden floor, loop and wander across the bark and boards, as if mapping constellations in the sky with a sticky, gummy trace.
The conker-sized garden snails, Cornu aspersum, are still active. I can’t recall a November this unseasonably warm, and it’s difficult to know what kind of confusing cues nature is now sending out. During a walk in the nearby public field, I noticed a few bats swooping overhead, likely waiting until the temperature falls before they enter hibernation. The snails in the shed, meanwhile, show no signs of hibernating anytime soon. Their silver, overlapping trails twist and tangle and form a chaotic map, a kind of spaghetti junction, indicating that for now, they’re far too occupied for a winter rest.
In the height of summer, when the weather was so warm and dry, I came across a cluster of snails, lying completely still, clinging to the base of an ivy plant on an old stone wall. Their brownish-grey, slimy bodies were fully withdrawn into their shells. This period of aestivation – a kind of ‘summer sleep’ – helps them survive long stretches of hot and parched conditions. The snails retract their foot – the muscular organ used for movement – into their shells and then seal the opening with a layer of mucus, which dries and hardens, forming a protective layer that traps moisture inside. Some snail species, such as the elongated, spiral-shaped door snails, don’t use mucus; instead, they close their shells with a small, calcium-rich plate which serves the same purpose. Snails can stay in this sleepy, summer-slumber state for months.
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Temporarily closing up shop during a heatwave isn’t a guarantee of survival – prolonged heat is fatal. The globular shells of common snails, with wide, white-lipped openings that spiral to a blunt tip, often make ready-made nests for other creatures, such as bees. Using snail shells as nests makes sense: the snail has already done the hard work of building the structure, and the hard shell is both robust and waterproof.
Empty snail shells make perfect nesting places for a small group of solitary mason bees, known as helicophiles, or ‘snail lovers’. The female bees live their lives as lone parents – the males mate, then die – so reusing a snail shell saves them time and energy. Before laying her eggs, a female will somehow push the shell to a sheltered spot. She then deposits her eggs, each with a ball of pollen, pressing them against the inner walls of the shell. To protect her emerging brood from predators, the female bee fills the opening of the shell with materials like sand and pebbles. Then she covers its exterior with bits of plant matter, transforming it into a camouflaged, fortified nursery. For this to succeed, they need us to leave areas wild and untouched.
In Ireland, the gold-fringed mason bee, first recorded in 1921 in Malahide, is most commonly found along the east and south coasts, from Louth to Cork. It typically nests in empty snail shells, ranging from the common garden snail to the glossy white-lipped snail. If it can’t find a shell, a field will do; in 2014, a dairy farmer in Tipperary, John Fogarty, observed a female nesting in a mound of peat near his farm in Horse and Jockey – the first ever time this bee was seen nesting outside abandoned snail shells in Ireland.
I take a closer look at the snails in the shed, their whorls serving as a kind of badge of maturity, revealing their approximate age. Each whorl is a complete 360-degree spiral turn of the shell, like a loop of a coiled spring, with the apex marking the oldest part. A baby snail has just a single small turn; by adulthood, it’ll have around five of them. Each shell coils clockwise, and all the ones I see are right-handed, which is usual. Left-handedness is extraordinarily rare – a one-in-a-million event. In 2017, a garden snail named ‘Jeremy’, discovered in a compost heap in London, made headlines as a ‘sinistral’, or lefty, anomaly.
With the cold snap, I imagine the common snails in the shed will huddle together in a hibernaculum – their winter quarters – gathering into a kind of “I’m not here, don’t look at me” pose against hungry song thrushes and blackbirds. And those that don’t survive the winter season might, by next spring, be repurposed into tiny nurseries – incubation sites for new bee life.
