Unicorn Snails (Subulina Octona)

Tiny tropical land snails with elongated, spiralled shells that taper to a fine point — hence the "Unicorn" name. Subulina octona is a small, active, highly social species that's ideal for nano enclosures, terrariums, bioactive setups, and as companions in tropical isopod displays. They're hardy, easy to care for, and one of the most engaging miniature snails available in the hobby.

Available individually, in groups of 5, or in groups of 10. Often known by alternative names: Awl Snail, Miniature Awl Snail, or Brazilian Trumpet Snail.

A Glimpse

• Scientific Name: Subulina octona
• Common Names: Unicorn Snail, Awl Snail, Miniature Awl Snail, Brazilian Trumpet Snail
• Family: Subulinidae
• Origin: Native to tropical Americas; now widely distributed globally (Caribbean, Africa, Asia, Australia, Pacific Islands, and as a "hothouse alien" in Britain and Czech Republic)
• Adult Size: 1.5–3 cm shell length (most stay around 2 cm)
• Lifespan: 2.5–4 years under good conditions
• Difficulty: Easy — genuinely beginner-friendly
• Temperature: 20–26°C (24–27°C optimal for activity and breeding)
• Humidity: 80% or higher — these are tropical snails
• Behaviour: Social, nocturnal, often hidden during the day
• Reproduction: Hermaphroditic, capable of self-fertilisation, prolific breeder

Why "Unicorn"?

The name comes from the shell shape. Unlike the rounded, dome-shaped shells of most familiar land snails (think garden snails or Giant African Land Snails), Unicorn Snails have a long, narrow, tapered shell that ends in a sharp point — like a tiny unicorn horn. The shell typically has 8–9 whorls and is glossy, semi-translucent, and yellowish-brown in colour. Through the shell you can often see the snail's body, and in adults you can sometimes see eggs developing inside.

The body is pale yellow and surprisingly long when extended — Unicorn Snails can stretch their body almost as long as their shell, which makes them entertaining to watch as they explore enclosures. They're inquisitive and active in a way that bigger snails often aren't, and they don't have the slow, ponderous movement of larger species.

Why Keep Unicorn Snails?

Several reasons make these one of the most useful and rewarding tiny invertebrates in the hobby:

Bioactive cleanup. Unicorn Snails are detritivores — they consume decaying plant material, lichens, fungi, fallen leaves, and biofilms. In a planted terrarium or bioactive enclosure, they help process organic waste before it accumulates. They work alongside springtails and isopods to keep substrate clean.

Tropical isopod companions. Unicorn Snails coexist beautifully with tropical isopod species in mixed enclosures. They share the same warmth and humidity preferences as Cubaris and Ardentiella species — 20–26°C and high humidity. They're too small to compete with isopods for resources and don't disturb breeding colonies. Many keepers add them to Cubaris display enclosures specifically because they're active during different hours (nocturnal) and add visible movement when the isopods are hidden.

Nano enclosures. Their tiny size (around 2 cm fully grown) means they thrive in small enclosures that wouldn't suit anything else. A 4-litre tub can comfortably house 10 or more Unicorn Snails. This makes them perfect for desk-top displays, classroom setups, or anyone with limited space.

Terrarium displays. In planted terrariums, the unicorn-horn shell shape stands out against natural backgrounds. They're constantly active in damp, planted environments and add visible life at the small scale.

Easy care for first-time invertebrate keepers. Unicorn Snails are forgiving of minor husbandry mistakes. They tolerate temperature variations, recover well from short humidity dips, and don't require specialist food. For someone new to invertebrate keeping, they're an excellent starter species.

Enclosure

A small plastic tub or glass terrarium works well. Cross-ventilation is important — drill or include vents on opposite sides of the enclosure to maintain airflow without dropping humidity too much. Unicorn Snails do well in setups that other tropical inverts use, so existing tropical isopod enclosures can host them without modification.

Substrate should be 3–5 cm of organic topsoil, peat-based soil, or a mix. Avoid stones, gravel, or sharp materials that could damage the delicate shell. Flake soil mixed in adds nutrition and texture they enjoy.

Provide leaf litter generously — magnolia leaves, bamboo leaves, and other dried hardwood leaves all work. Unicorn Snails will graze on the leaves themselves and on the biofilms that develop on them.

Add hides — small pieces of cork bark, moss patches, and pieces of wood. Snails like to bury or tuck themselves away during the day, so multiple hide options reduce stress.

Temperature and Humidity

20–26°C is the comfort range, with 24–27°C optimal for activity and reproduction. Most UK homes will sit within the lower end of this range at room temperature; supplementary heat (a small heat mat on a thermostat) extends the comfort range during winter and encourages breeding.

Humidity should be 80% or higher. Mist daily to maintain damp substrate. Unicorn Snails breathe through a lung-like cavity that requires high atmospheric moisture — a dry enclosure causes rapid health decline. The substrate should always feel damp to the touch.

Diet

Unicorn Snails are herbivores and detritivores with broad appetites:

• Fresh vegetables: Cucumber, courgette, sweet potato, carrot, lettuce (avoid iceberg), spinach, kale, broccoli
• Fruit (occasionally): Apple, banana, melon, mango — avoid citrus
• Leaf litter: The foundation of their diet. Hardwood leaves provide both food and grazing surfaces
• Biofilms and lichens: Naturally consumed off leaves and wood as the enclosure matures
• Calcium: Essential — see below

Tip: Slice fresh vegetables thinly. Unicorn Snails have small mouths and can struggle with thick chunks.

Calcium

Calcium is essential for shell health. Around 98% of a snail's shell is calcium carbonate, and without consistent calcium intake, the shell becomes thin and fragile.

• Cuttlebone — leave a piece in the enclosure permanently. Snails will rasp on it as needed
• Malawi Limestone — passive calcium source plus habitat structure
• Crushed eggshell or oyster shell — additional supplementary options

Breeding — Be Prepared

Unicorn Snails are extremely prolific. They're hermaphrodites, meaning every individual has both male and female reproductive organs. Two snails will breed readily, and even a single isolated Unicorn Snail can reproduce through self-fertilisation under the right conditions.

Each reproductive event produces 4–5 eggs, but a single snail can have 18–33 reproductive events over its lifetime — totalling around 124 eggs per snail. In a colony, you can quickly end up with hundreds of snails if you don't actively manage the population.

Eggs are visible through the parent's translucent shell before being laid into the substrate. If you don't want population growth, eggs need to be removed and frozen (humanely destroying them) before they hatch. This isn't optional in a long-term colony — Unicorn Snails will overrun an enclosure within months if left unchecked.

If you do want to breed them, no special intervention is needed. Maintain good conditions and offspring will appear automatically.

Note: Like all snails, Unicorn Snails should never be released into the wild in the UK. They're a tropical species that wouldn't naturally survive UK winters, but eggs and small specimens can survive in heated environments (greenhouses, hothouses) and have established populations in the UK as "hothouse aliens."

Tank Mates

Unicorn Snails work well with:

• Tropical isopods — Cubaris and Ardentiella species share the same conditions and don't disturb the snails. Avoid pairing with aggressive isopod species like large Porcellio that might attack small snails
• Springtails — perfect bioactive companions, sharing the same humidity preferences
• Other Unicorn Snails — they're highly social and thrive in groups. Solo specimens often live shorter lives than those kept communally
• Bioactive vivariums — for dart frogs, mourning geckos, and other small humid-loving herpetofauna, Unicorn Snails serve as cleanup crew without being eaten (their shells make them unpalatable to most small predators)

Avoid pairing with: large isopod species that may crush them, predatory invertebrates, or large snails (like Giant African Land Snails) that could accidentally crush or outcompete them.

Pairs Well With

Building a complete Unicorn Snail or mixed bioactive setup:

• Flake Soil — nutritious substrate component
• Magnolia Leaves — long-lasting leaf litter
• Bamboo Leaf Litter — structural leaf cover
• Cuttlebone — essential calcium for shell health
• Malawi Limestone — passive calcium source
• Springtails — bioactive cleanup companions
• Cubaris isopods — ideal mixed-enclosure companions
• Enclosures & Air Vents — properly ventilated housing

Browse the full Other Invertebrates collection for more species, or our setting up guide for a complete enclosure walkthrough.