What Do Snails Eat and Drink? Garden, Pond and Pet

Snails rasp their food rather than bite it, and they take in most of their water through the skin rather than by drinking. Both facts explain a lot about where they turn up and what harms them.

How a snail eats at all

The mouth contains a radula — a flexible ribbon covered with thousands of microscopic teeth, worked back and forth across the food like a file. Worn teeth are continuously replaced from behind, conveyor-belt fashion.

That is why snail damage looks the way it does: irregular holes with smooth, scalloped edges, often in the middle of a leaf, rather than the clean-cut edges a caterpillar leaves.

What is on the menu

The calcium part is not optional. A snail’s shell is calcium carbonate, and it has to come from somewhere — so snails actively seek out chalk, limestone, old lime mortar, cuttlebone, and the empty shells of dead snails. It is the reason snail numbers are so much higher on chalky soils than on acidic ones.

What do they drink?

Very little in the way we mean it. A land snail’s skin is highly permeable, and it takes up water directly from:

• Damp soil and leaf litter, through the underside of the foot
• Dew and rain film on leaves and stems
• Humid air, to a degree

It will also lower its head to a shallow film of water and take some in through the mouth. But a snail sitting in a saucer of water is not drinking well — it is at risk of drowning.

Feeding a pet snail

Good staples, all washed and unsprayed:

• Lettuce (not iceberg — mostly water), spinach in moderation, kale, broccoli leaves, dandelion leaves
• Cucumber, courgette, carrot, sweet potato, pumpkin
• Apple, pear, melon, banana, berries
• A permanent cuttlebone, for the shell

Never:

• Salt or anything salted — it draws water straight out through the skin
• Citrus, tomato and other acidic foods — acid attacks the shell
• Bread, pasta, sugar, processed food, milk and dairy
• Anything that may carry pesticide residue. A snail absorbs contact far more readily than a mammal does, so garden greens from a treated lawn are a real risk.

Do snails eat each other?

Some genuinely hunt. The decollate snail and the rosy wolfsnail are predatory, and among slugs the big spotted leopard slug eats other slugs and is worth leaving in a garden on purpose.

Most ordinary garden snails are not predators but will readily eat a dead snail — the body as food, the shell as calcium.

Why they vanish and come back

In dry or cold conditions a land snail withdraws and seals the shell opening with an epiphragm, a dried mucus membrane, and becomes dormant. In that state it needs almost nothing and can wait out weeks, and some desert species far longer.

So the snails that “disappeared” during a hot dry fortnight did not go anywhere. They are sealed under a pot rim or in a wall cavity waiting for rain — which is why the first wet evening afterwards produces so many at once.

Turning the diet against them

Knowing what they want tells you where to intervene:

• Water in the morning, not the evening, so the soil surface is dry during their active hours.
• Clear the daytime shelter they retreat to: upturned pots, boards, dense groundcover, long grass beside beds.
• Remove the decaying material that supports a resident population close to the vegetable bed.
• Protect seedlings only. Most damage is done to plants in the first few weeks; mature plants shrug it off.
• Encourage the predators that eat them — frogs, toads, hedgehogs, slow-worms, thrushes and ground beetles. A pond does more over a season than any barrier product.