In the wild, hermit crabs are omnivorous and opportunistic scavengers. Hermit crabs do not hunt down live prey. Instead, they sustain themselves on what they can find. In captivity, you can tailor the diet of hermit crabs to ensure all nutritional needs are met.
Hermit crabs need a diet rich in protein and calcium to promote a healthy color and strong exoskeleton. Meat and fish, eggs, nuts, and leafy greens are safe for hermit crabs to eat. Fresh fruit is a popular choice as most hermit crabs have a sweet tooth. Hermit crabs will also consume any wood, moss, or algae in their habitat.
Knowing what to feed hermit crabs is critical. Do not make the mistake of assuming that, because hermit crabs are scavengers, they can eat anything. Poor nutrition can be harmful to hermit crabs.
Are Hermit Crabs Carnivores or Herbivores?
Hermit crabs are omnivores, which means they will eat a plant-based or meat-centric diet. As natural scavengers, wild hermit crabs cannot be fussy about food. They will eat an apple core or the carcass of a dead conspecific.
The most important consideration is the make-up of their food. Hermit crabs need protein and calcium above all else. This keeps them strong and healthy. Appropriate levels of carbohydrates also provide energy.
One positive of scavenging is that hermit crabs are never short of options. As per the Journal of Experimental Marine Biology and Ecology, they rarely eat the same thing twice in any 24 hours.
This means that hermit crabs fully embrace their omnivorous nature. No hermit crab will ever gorge exclusively on meat or plant-based matter. Dietary diversity is critical to keeping hermit crabs interested in food.
How Do Hermit Crabs Eat?
Hermit crabs rely upon their pincers, scientifically known as the chelipeds, to eat. Healthy, intact hermit crabs have two chelipeds at the front of their body. These are often considered the foremost pair of legs on the anatomy of hermit crabs.
In most cases, the right cheliped is larger and dominant. Hermit crabs use this pincer to pick up food and bring it toward their mouth. The smaller cheliped may then be used to guide the food into the mouth.
Hermit crabs do not have teeth, but small mouthparts. These are used to grind up any food until it small enough to swallow. This means that captive hermit crabs flourish when food is provided in small, bite-sized chunks.
This will also reduce food waste. As hermit crabs are small, they do not eat significant amounts. Most will be content to nibble until no longer hungry, then move on with their day. If a hermit crab is gorging on food, it is likely preparing to molt.
If your hermit crabs have shed their chelipeds, they’ll need to be hand-fed. For small snacks, this can be done from your palm. Not all hermit crabs tolerate handling well, though. In these instances, feed your hermit crabs by offering food on a plastic spoon.
How Often Do Hermit Crabs Eat?
Hermit crabs can survive for several days without food, sometimes as long as two weeks. If a hermit crab knows that it will be without access to food for a prolonged period, it will eat to excess. The more fat a hermit crab consumes, the longer it can safely fast.
Most hermit crabs will avoid this eventuality. Even if a hermit crab is scheduled to molt, and will be unable to scavenge for weeks, it will eat its shed exoskeleton. This provides all necessary calories and nutrients until it resurfaces to scavenge again.
Just because hermit crabs can live without food, it doesn’t mean they should. Like any animal, hunger impacts the behavior of hermit crabs. As per the Bulletin of Marine Science, ravenous crabs grow aggressive and cantankerous. This is especially likely if food is scarce.
In the wild, hermit crabs will typically eat once a day. They emerge once the sun goes down and look for nourishment. This should be replicated in captivity. Place food in a habitat just before dusk. This is when your hermit crabs will wake up, likely feeling hungry.
What Do Wild Hermit Crabs Eat?
This depends on whether the hermit crabs dwell primarily on land or in the ocean. Many wild species of hermit crabs are strictly aquatic. They will remain on the floor of the seabed, rarely surfacing. These hermit crabs sustain themselves on:
- Coral reefs
- Mollusks and small snails
- Dead animals
Land hermit crabs, meanwhile, will not enter the water unless strictly necessary. Many species of fish and other marine lifeforms are natural predators of hermit crabs. A land-based crab cannot effectively defend itself from such foes.
This means that terrestrial hermit crabs typically scavenge after sundown, seeking nourishment from:
- Moss and leaves
- Food left by human visitors to the beach
- Fecal matter
- Cadavers of dead animals
If you bring hermit crabs into your home, initially attempt to replicate a wild diet. This will help the hermit crabs adjust. Hermit crabs experience post-purchase syndrome. This is a period of intense stress caused by the transition from wild to captive life.
What Do Hermit Crabs Eat in Captivity?
A more pertinent question should be, “what do hermit crabs like to eat?” By spoiling your hermit crabs with safe yet delicious foods, life in captivity will be more agreeable.
Many hermit crabs struggle with adaptation to life as a pet. Review this safe hermit crab foods list and provide a tasty, varied diet. This will improve their quality of life no end.
Contents of an Aquarium
As we mentioned previously, wild hermit crabs will sustain themselves on anything they find in their environment. This survival instinct is retained in captivity. Do not be surprised or alarmed if your hermit crabs eat wood, moss, algae, or corals in a tank.
This is the reason why many people adopt marine hermit crabs. They act as janitors in a fish tank, preventing unsightly algae from overflowing. Land hermit crabs will also nibble on organic elements of their habitat.
Ensure that any wood you use in a habitat is sage for hermit crabs to consume. Regularly spot clean an aquarium, too. If hermit crabs get into the habit of eating their environment, they may consume deadly mold growths.
The habitat of your hermit crab will likely become its very own ecosystem. Many different insects will make a home within the aquarium. While these will need to be purged by cleaning every couple of months, they serve a purpose in the meantime.
Hermit crabs are not natural hunters, but they will eat insects found in their habitat. This can be a great way for hermit crabs to supplement their diet. Captive crabs should not sustain themselves on insects alone, but they are an appealing side dish.
Having said that, do not get live insects from a pet store for your hermit crabs. Given a choice, your pets will seek other food. Adding unnecessary lifeforms to a habitat could upset the natural balance of the aquarium.
If you keep aquatic hermit crabs, there is every chance they will share a tank with fish. In such an instance, you’ll find that your hermit crabs help themselves to leftover fish flakes. This is fine, provided the food is offered in moderation.
Check the ingredients of your chosen fish food. Ensure it does not contain any untoward chemicals. That should be standard practice, to protect your fish and crabs alike. If it’s safe, hermit crabs will love these floating treats.
So much so that high-quality fish flakes can even be used as a treat for terrestrial hermit crabs. Fish food should not be the cornerstone of your pet’s diet. It makes an interesting addition, though.
Cuttlebone is an advisable addition to any hermit crab enclosure. You can grind cuttlebone into powder and add it to food or leave a free-standing slab of cuttlebone in the substrate. Hermit crabs will work their way through the latter at their leisure.
Cuttlebone is the skeleton of the cuttlefish, a cephalopod that resembles a squid. This skeleton is packed with calcium, making it ideal for hermit crabs. Unlike most foods, you can also provide cuttlebone constantly. Hermit crabs are unlikely to tire of this ingredient.
This is because cuttlebone provides entertainment as much as nourishment. Hermit crabs like to interact with obstacles in their environment. A cuttlebone can be constantly pinched and nibbled.
Fresh Fruit and Vegetables
Fruit and vegetables are essential to the diet of hermit crabs. Whenever you head to the supermarket, stock up on fresh, organic produce. The sweeter the better, as far as hermit crabs are concerned. Strawberries, grapes, bananas, and peppers are all firm favorites.
You can offer leafy greens to hermit crabs, too. These are usually packed with calcium, so they’re a great addition to the diet. They lack any distinct scent, which means that hermit crabs may initially reject these foods.
The presence of insecticides or herbicides is lethal to hermit crabs. Organic produce significantly reduces this risk.
Meat and Fish
As discussed, hermit crabs are omnivorous. This means they are not averse to eating meat. As per Marine Ecology Progress Series, hermit crabs can even resort to cannibalism. It is common for these animals to consume dead comrades, both in the wild and in captivity.
This does not mean that hermit crabs are best served raw meat or fish. Always pick up the highest-quality products that you can. Check it has not been treated with any potentially harmful preservatives. Cook the meat thoroughly, allowing it to cool before serving.
Hermit crabs have small bodies and appetites, so they will not need an entire steak. Be mindful of this, as meat can spoil and create bacteria in a habitat. Cut meat into small, bite-sized chunks and serve it sparingly.
Next time you are making yourself a healthy breakfast of oatmeal, consider setting some aside for your hermit crabs. They often love oatmeal, especially if sweetened with honey.
Go easy on the milk if offering oatmeal to hermit crabs, though. Lactose is often disagreeable to these animals. If you use oat-based milk for moisture, so much the better.
In addition to oatmeal, you could also offer oatcakes for your hermit crabs to nibble on. These products can be broken apart and tackled at will. They also do not rot, ensuring that you will not need to worry about bacteria forming within a habitat.
Offering protein in abundance, eggs are a great food for hermit crabs. Scrambled eggs, in particular, will be consumed by your pets. You could also boil and slice eggs for hermit crabs.
Be mindful of how you cook eggs. Do not add anything that would appeal to the human palate, such as salt or pepper. The eggs themselves are more than enough to satisfy your hermit crabs.
Hermit crabs will also benefit from consuming eggshells. Grind these shells up into small pieces and mix them with scrambled eggs. This will provide a further source of calcium.
Nuts, Seeds and Grains
Hermit crabs love seeds and nuts. Happily, these foods are also beneficial due to their high protein content. Hermit crabs also do not need to worry about the fat in nuts. This can benefit your pets, especially ahead of a molt.
Crush nuts into a fine powder, or chop them small and serve in a bowl. Remember that hermit crabs do not have teeth, and nuts are tough. Any serving too large is a choking hazard. You could also popcorn to your hermit crabs. They will love you for it.
The following are believed to be among the favorite nuts and seeds enjoyed by hermit crabs:
- Brazil nuts
- Pumpkin seeds
- Sunflower seeds
Avoid seeds from fruits as they often contain arsenic. While it is known if this will harm hermit crabs, the potential for choking ensures that such foods remain best avoided.
Peanut Butter and Jam
Peanut butter is a good treat for hermit crabs, as is a fruity jam. There is a caveat, though. While hermit crabs love these foods, they should be hand-fed from the tip of a finger.
If you leave a jar or spoonful of loose peanut butter in an enclosure, your hermit crabs will amass at a rate of knots. Hermit crabs are messy eaters.
Hermit crabs could get this ingredient clogged in their gills, making breathing difficult. This can lead to suffocation. Any foodstuff that is not solid should never be left to be consumed unsupervised.
There is nothing wrong with treating your hermit crabs to a teaspoon of peanut butter or jam. Just take care to ensure it ends up in its mouth, and nowhere else.
Hermit Crabs Unsafe Food List
You may be forgiven for thinking that hermit crabs have iron constitutions, capable of eating anything. After all, if they survive in the wild by scavenging, they must occasionally find undesirable nourishment. While this is true, it also negatively impacts hermit crabs.
As per The Biological Bulletin, hermit crabs avoid foods that previously made them unwell. The journal refers to this as, “serious physiological upset,” typically associated with emotional responses.
This suggests that hermit crabs remember the unpleasant side-effects of eating food that made them unwell. Hermit crabs have surprisingly good memories, and as per Animal Behavior, certainly recall painful experiences.
Feeding inappropriate food may damage the trust your hermit crabs have in you. To this end, you need to understand which foods are unsafe and unsuitable for hermit crabs. This list is not as exhaustive as the approved food list above but is arguably even more critical to learn.
Hermit Crab Pellets
If you’re new to caring for hermit crabs, pellets seem to be an easy dietary option. After all, these commercial foods are designed with hermit crabs in mind. The effectiveness of pellets is a source of debate among experienced crabbers, though.
In theory, hermit crab pellets are palatable, appropriately sized sources of everything a hermit crab needs. Think of this foodstuff as the equivalent of small animal muesli. In reality, many hermit crab enthusiasts consider pellets to be toxic.
It is claimed that pellets contain harmful preservatives, in addition to heavy metals such as copper. These ingredients can be fatal to hermit crabs. A common claim is that pellets are constructed from general food waste that is bound together.
If you insist on feeding hermit crab pellets, dedicate time to research. Learn exactly what is in the pellets and how they are made. Even then, there is no guarantee that your pets will eat the pellets. Many hermit crabs find them dull and devoid of flavor.
Overall, pellets are a false economy. You are better served by offering fresh food to your hermit crabs. As you’ll see from the list above, you will have no shortage of options.
Moldy or Aged Foodstuffs
If hermit crabs are scavengers, they will likely eat moody or spoiled food in the wild on occasion. This does not mean that such food is good for them, though. If you have spoiled food, throw it in the garbage. Your hermit crabs are not organic waste disposal units.
Use your discretion here. A slightly wrinkled grape, for example, is fine. Hermit crabs will not be concerned by the texture. It will still taste the same to them. If the fruit is actively rotten, it is just as unsafe for hermit crabs.
The same applies to spoiled meat. Feeding such food to hermit crabs will make them sick, or worse. You can safely feed hermit crabs with fresh produce without breaking the bank. Do not resort to hazardous, spoiled sustenance.
Not actually a foodstuff, but critically important to note all the same – hermit crabs cannot drink water straight from the tap. The presence of chlorine and copper in unfiltered tap water kills hermit crabs.
Hermit crabs need water to drink to survive. The safest option is to purchase spring water by the bottle, though. Alternatively, get a water purifier or distill the tap water at home.
Tap water leads to a painful demise for hermit crabs. The aforementioned topical chemicals and heavy metals cause blistering and scarification of the gills. Suffocation will follow, after intense pain and discomfort.
This hazard applies to all uses of tap water around hermit crabs. Leave no trace of chlorine in a habitat after cleaning, and never bathe hermit crabs in a basin or bowl of tap water.
Saline water is an essential addition to any hermit crab enclosure. Hermit crabs rely upon saltwater to activate their senses, most notably smell. As per Proceedings of the Royal Society, saltwater vapors aid hermit crabs in detecting food aromas.
The salt applied to dechlorinated water in a hermit crab tank cannot be table salt, though. This kitchen cupboard staple contains large quantities of iodine. Iodine is an essential chemical element in human consumption, promoting a healthy thyroid gland.
Hermit crabs also need small quantities of iodine to aid a healthy, timely molt. It is easy for hermit crabs to get too much iodine, though. This causes toxicity that kills hermit crabs. Your hermit crabs will get the iodine they need from the approved foods we previously listed.
When mixing salt into water, use marine salt. If you run out, do not use table salt as a substitute. Rush through an urgent order and try hand-feeding your hermit crabs in the meantime.
Pesticides and Herbicides
When discussing fresh fruits and vegetables earlier, we recommended getting organic to avoid harmful chemicals. It is not just fresh produce that merits this investigation, though. Some meats, for example, are treated with ethoxyquin.
Any kind of artificial chemical is harmful to hermit crabs. This means you’ll need to vigilant about keeping such materials away from your hermit crabs. This also means being careful about using potting soil as an alternative substrate or gathering wood from nature.
If you have any doubt as to whether the food contains pesticides or herbicides, keep them away from your hermit crabs. Washing in cool water may remove any toxins.
Onions and Garlic
Hermit crabs cannot develop anemia, but this does not make onions or garlic safe. These foods are considered fatal to insects. While hermit crabs are crustaceans, not insects, they are invertebrates. This means they share many qualities with their six-legged brethren.
This issue is complicated by the fact that commercial hermit crab foods will contain traces of onion. This is typically due to the strong scent of the vegetable. Refer back to what we said about pellets, though. This is another reason to avoid such foods.
Popular consensus claims that citrus fruits, such as oranges and lemons, are toxic to hermit crabs. Technically, this is untrue. The belief stems from citrus trees, the bark of which does contain natural anti-pesticides.
Even so, there is nothing to gain by attempting to feed citrus to hermit crabs. There is always the slim chance that comes of these toxins have seeped into the fruits themselves.
What’s more, most hermit crabs will show no interest in citrus fruits. The scent alone of these foodstuffs will likely deter them from approaching. Even the smallest slice of lemon or orange in a fruit selection may make an entire meal unpalatable to your pets.
Hermit crabs are not fussy eaters, but this does not mean you can offer them anything. You must meet the nutritional and lifestyle needs of your hermit crabs. More importantly, avoid anything that would do them harm.