It’s a summer tradition in many beach and boardwalk towns: you buy the kids a hermit crab in a brightly painted shell, take it home, and then, usually, it dies. You figure they don’t live very long, and move on.

But for Carol Ormes it turned out to be a bit more of a commitment. When a friend bought a crab on a trip to Ocean City, Md., Ormes says, “I said that that was the ugliest thing I ever saw – I don’t want that in my house! But after a week of it crawling around the house, I fell in love with that little guy.”

So she got Jonathan Livingston Crab on the way home from the beach, and his friend Crab Kate later at a mall. They now live with Ormes at a retirement community in Fort Myers, Fla., and are about to turn 32 years old.

Ormes is a bit of a local celebrity – “The crabby lady, they call me” – although not everyone is clear on the source of her fame: at a local restaurant recently, “someone asked, how are your snails?”

They’re not snails, nor particularly closely related to the crabs we eat. And Ormes is far from the only one who loves them. You can find a thriving community of hobbyists on the Internet who appreciate these critters and share advice on how to keep them.

Contrary to what you might think when you buy the little critter, it does take a little attention to keep them healthy – which also means they’ll be more fun.

The basic setup should include:

– Substrate: Crabs are often sold with gravel in the container, which you’ll need to replace immediately with sand, or coconut fiber bedding that you can buy in pet stores. Keep it moist (not soggy) and deep enough for your biggest crab to bury itself completely. Otherwise the crab will be unable to molt, and will die.

– Enclosure: Crabs need room to move around and places to climb and hide. Also, remember that the hermit crabs we buy as pets are tropical: provide a heat source, and don’t use wire cages – they don’t retain humidity.

– Extra shells: The unique feature of the hermit crab is that it wears another animal’s shell for protection, so you need to provide a choice of bigger shells as it grows. “Imagine if we stayed in the same clothes since we were in kindergarten!” says Eleanor Glazewski of Shrewsbury N.J., who sells shells and other supplies at www.elsshells.com. She cautions against painted shells, they chip, and the crabs can eat the paint. Make sure to have several for each crab in a tank; they may fight over them otherwise.

– Water: Crabs need chlorine-free water. Glazewski suggests that since they only need a dish of water, not a whole tank, you can use bottled water instead of buying aquarium dechlorination chemicals. The more exotic species require a dish of saltwater as well, which some hobbyists also provide for the usual purple pincher that’s sold in pet stores and souvenir shops. You can get saltwater mix at the petstore; since you’ll be using small amounts compared with a full aquarium, one package will last for months.

– Food: As for food, crabs in the wild are scavengers. “They eat pretty much whatever falls from the trees and washes up on the shore,” says Aaryn Wika of Northglenn, Colo., who sells her own natural food mixtures at www.thehappyhermitcrab.com.

The wide variety of mixes on her Web site are made from human food ingredients, even the seaweeds – everything, she says, except the krill. So go ahead and supplement your crab’s diet with bits of your own fruits, vegetables, and seafood. (Wika cautions not to feed them garlic, onions, or table salt, and while they like popcorn, no butter.)

Wika warns that if you buy commercial foods, be careful of preservatives, especially copper sulfate. Copper is actually used as a medication for fish to eliminate invertebrate parasites, so should never be fed to an invertebrate like a hermit crab, says Shane Boylan, veterinarian at the South Carolina Aquarium.

Finally, when you pick a crab to buy, try to find a store that looks like it’s following these care instructions; for example, if they’re kept in wire cages, they are likely already dehydrated and in poor health. With a good start and the right care, your crab should last through many more summers. You probably won’t beat Carol Ormes’ record, but who knows – as she says, “I didn’t realize this would be a lifetime adventure.”