Hermit crabs are one of the most unique and fascinating pets you can own. Their quirky personalities, social behaviours, and constant need to explore make them a joy to watch. However, one of the key aspects of hermit crab care that new and even experienced owners sometimes overlook is the importance of providing extra shells. Hermit crabs don’t grow their own shells; instead, they rely entirely on empty shells to protect their soft, vulnerable abdomens. As your crabs grow, they will need to change shells frequently, making it essential to have a variety of sizes and shapes on hand. Understanding why hermit crabs need extra shells, how to choose the right ones, and how to maintain them is crucial for their health, happiness, and longevity.
Why Hermit Crabs Need Extra Shells
Hermit crabs have soft abdomens that are highly susceptible to injury, dehydration, and predation. Their shells serve as a protective home, shielding them from these risks. Unlike other animals, hermit crabs do not produce their own protective covering, so finding suitable shells is essential to their survival. As hermit crabs grow, their current shells may become too small or ill-fitting. When this happens, they must find a larger shell to move into. In the wild, hermit crabs have access to a wide variety of discarded shells from marine snails and other mollusks. In captivity, however, they are limited to what their owners provide. If suitable shells aren’t available, hermit crabs may face stress, competition, and even injury. Competition can lead to aggressive behaviour, fights, and in extreme cases, damage to the crab’s soft abdomen, which can be fatal.
Providing extra shells encourages natural behaviour such as shell exploration, selection, and swapping. Hermit crabs are known to inspect multiple shells before choosing the one that fits best. Having a variety of options allows them to express this instinctive behaviour, keeping them active, engaged, and mentally stimulated.
Choosing the Right Shells
Selecting the right shells for your hermit crabs is more than just picking something that looks good. Shells vary in size, shape, and material, and all of these factors affect your crab’s comfort and safety.
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Size: Hermit crabs need shells that are slightly larger than their current one to allow for growth. A shell that is too small will be uncomfortable and may restrict movement, while a shell that is too large may make the crab feel insecure or make climbing difficult.
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Shape: Different hermit crabs have different preferences when it comes to shell shapes. Spirals, conches, and round-bodied shells are popular choices. Providing a variety allows crabs to select a shell that suits their body shape and behavioural needs. Some crabs prefer shells with wide openings for easy entry, while others may choose deeper shells for protection.
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Material: Always choose natural, untreated shells. Avoid painted or chemically treated shells, as hermit crabs may nibble or live in them for extended periods. Toxic substances can harm your crab’s health.
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Quantity: It’s recommended to provide at least two to three extra shells per crab. This reduces competition and ensures that every crab in a group has access to a suitable shell when needed. In communal tanks, multiple shell options are critical to maintain harmony and prevent stress-related behaviours.
High-Quality Shell Options
At Woonona Petfoods, we stock a variety of natural shells that are safe and suitable for hermit crabs of all sizes. Some excellent options include natural marine shells collected responsibly and carefully cleaned to remove debris. These shells come in multiple sizes and shapes, allowing you to offer your crabs a selection similar to what they would find in the wild. Extra-large shells are useful for mature crabs or those that are still growing rapidly, while smaller shells ensure juvenile crabs always have access to appropriately sized options. Offering a mix of textures, openings, and spiral directions can encourage exploration and enrichment.
Maintaining Shells
Maintaining clean and safe shells is just as important as providing extras. Before placing a new shell in your crabitat, wash it thoroughly in warm water to remove dust, sand, or organic debris. Never use soap or chemical cleaners, as residues can be toxic to hermit crabs. Regularly inspect shells for cracks, sharp edges, or damage. Damaged shells can injure crabs, especially during climbing or fighting for a preferred shell. Remove any shells that are no longer safe, and replace them with fresh, clean options.
To encourage exploration and natural behaviour, rotate shells periodically. Placing new shells in different areas of the tank or slightly altering the layout can stimulate curiosity and activity. Hermit crabs are highly inquisitive and will often investigate every new shell they encounter, which is beneficial for their mental and physical health.
The Role of Shells in Social Behaviour
Hermit crabs are social animals that often interact with each other during shell changes. In the wild, crabs may form queues and wait their turn to swap shells. In captivity, a lack of extra shells can lead to competition and stress. By providing a variety of shells in the tank, you minimise aggressive behaviour and encourage positive social interaction. Some hermit crabs are very selective and may refuse shells that don’t meet their specific preferences. Having multiple options on hand ensures that every crab has access to a shell it is comfortable with, preventing prolonged stress and promoting healthy growth.
When to Offer New Shells
Monitor your hermit crabs’ growth regularly. When a crab begins to outgrow its shell, indicated by protruding legs or abdomen, it’s time to provide larger options. Even if the crab is not actively looking for a new shell, having extras available encourages voluntary shell swapping and prevents competition. It’s also a good idea to provide extra shells during times of stress or environmental changes, such as when introducing new crabs or rearranging the tank. Hermit crabs often explore new shells when feeling insecure or curious, so maintaining a stock of safe shells helps them adjust comfortably.
Hermit crabs rely on shells for protection, growth, and comfort, making extra shells a vital part of their care. By offering a variety of sizes, shapes, and natural options, maintaining clean and safe shells, and monitoring your crabs’ growth, you can create a thriving environment that encourages natural behaviour and reduces stress. Proper shell provision not only keeps your hermit crabs healthy but also enriches their lives, making them more active and engaged pets.
At Woonona Petfoods, we stock a wide selection of safe, high-quality shells and can help you choose the right options for your hermit crabs’ size and needs. With the right shells on hand, you’ll ensure your crabs are always prepared to grow, explore, and stay protected in their habitat.
