The ubiquitous and relatively inexpensive hermit crab is better served by hobbyists—and retailers—who are willing to invest some time and money into providing these creatures top-notch care.
One of the most popular and least discussed exotic pets is the land hermit crab. Even stores that have, for all intents and purposes, no livestock at all will often have a tank of hermits at the counter. I almost always have them on hand myself. And, to tell the truth, it makes me a little crazy, and for a couple of reasons.
In my last column I mentioned the most painful bites I have received in nearly 40 years of professional animal care, and at the top of the list was a pinch from a little hermit crab. They are not aggressive, or even actively defensive; the pinch is merely their overzealous grip as they maneuver about. Nonetheless, the pain from a pinch is such that it might in fact permanently terrify a small child and ruin his or her future relationships with all small creatures. The notion that these are harmless animals is widely held by the general public and often confirmed by pet store personnel. But it is not completely true, and as a pet professional you should really make that clear to your customers.
There is a bigger issue with hermit crabs, and it is an ecological and ethical one. Land hermit crabs (as opposed to marine hermits, a totally different group of creatures) are in fact as wedded to the sea as their aquatic cousins. They return to the ocean to breed, and spend the lengthy larval portion of their lives at sea. While captive breeding has occurred, it is not the source for the pet trade. This is one of the last largely wild-collected exotic pets, and while they do not yet seem to be at risk, it is seemingly inevitable that eventually they will get there. And thus, we as pet professionals are caught on the horns, or claws, of an ethical dilemma.
You may well decide to not carry them as a result of these factors, and, if so, I applaud you. I do continue to sell them on the theory that the ones that go home from my shop will at least lead longer and better lives than those acquired from stores that will neither warn their clients of the pinch risk or their wild origins. I also try to get my clients to consider other bugs that do not come with the same problems. Sad to say, tarantulas and roaches do not seem to garner the same “cute quotient.” Ah, well.
Yes, hermit crabs are adorable. They skitter about, waving their antennae, curious and unduly full of personality. Initially shy, especially as they adjust to a new cage, they eventually become very outgoing, and seem to possess excellent vision and a sharp sense of smell. They are naturally nocturnal, but are easily awakened and activated by nothing more complex than a misting of warm water.
Their popularity even extends past the “first pet” crowd. Over the years, I have had many customers who were on the lookout for specific species of hermit, as there are as many as six on the pet market. The most common are the Purple Pincher (Coenbita clypeatus) and Ecuadorian (C. compressus). There are even hermit crab societies, as a quick search of Google will reveal. For many, the love of these creatures is quite serious business.
Like other small and inexpensive animals, hermits are subject to what I like to call the “tropical fish factor.” That is, while the animal itself may cost only a few bucks, to set it up properly, one must be ready to invest exponentially larger amounts of money. This is often a hurdle for some clients, who, to their and their pet’s inevitable detriment, opt to shop where they are happy to sell a crab and a small plastic cage, no questions asked (or worse, answered). To me, that’s a dismal way to do business. Those who stay in my store, and opt for a crab, acquire a suitable glass tank and necessary supplies.
Plastic cages are difficult to heat without also melting the cage; wire cages cannot contain the high humidity the crabs require. Crabs should have an under-tank heater to provide an ambient heat—mid 70s to mid 80s is ideal—and an overhead spot for an intense basking point. The bottom heat will also help ensure high humidity in the cage, an absolute essential for crabs.
Crabs need two sources of water: saltwater for soaking and wetting their gills, and fresh or mildly brackish for drinking. They should have plenty of cage furniture, as they are climbers and determined little explorers. For bedding, I recommend sand. Coco fibre is also acceptable, although I find it makes the cage a bit messy. All other beddings tend to get moldy, inhibit crabs’ ability to burrow or present other problems. There are a number of perfectly fine prepared diets for hermit crab on the market, but, as with almost all prepared foods, they are best used as an occasional support diet to a wide variety of table scraps—the crabs are true omnivores—and an occasional freshly killed goldfish.
The other essential for hermit crabs is a wide variety of extra shells. Hermit crabs grow by molting, and, as they grow, they need a constant source of new housing. I have personally watched a crab over a few days’ time make the rounds of five other shells within his cage, carefully inspecting and testing. The shells were very similar to my eye; then again, I was not determined to live in one. After a few days, I looked in to see the crab’s molt and him in his newly chosen home.
One important warning about the shells: I only use natural shells. I never go for the painted shells. There is a strong possibility that crabs exposed to the paint will ingest toxins and die within a few months. Because the death is slow, the cause is rarely ascribed to the paint, but evidence suggests that it is a strong factor in shortening their little lives.
Some people claim that hermit crabs are social, but I have never witnessed any behavior that struck me as being particularly interactive. On the other hand, they certainly are communal, and as long as they are relatively close in size, they do well in groups. The big advantage of having groups of small animals like this is the increase in activity that they inspire in each other and, I find, their keepers. Kids love to watch them at work, and diligent observation will reveal subtle differences in personality, even amongst such a seemingly simple creature.
I am, of course, talking about the crabs, not the kids.
Owen Maercks has enjoyed being immersed in the world of professional herpetoculture for nearly 30 years. His store, the East Bay Vivarium in Berkeley, Calif., is one of the oldest and largest herptile specialty stores in the U.S.