A hamster that moves about on little wheels appears to have become this holiday season's unlikely must-have toy.

"Honestly, I don't really get it," said BMO Capital Markets analyst Gerrick Johnson, based in New York. "But I don't need to get it for a toy to be hot."

The hamsters, called Zhu Zhu Pets, are as cute as the next furry mechanical animal, but what seems to set them apart are the accessories: the mazes that children can build and rearrange, the cars the hamsters drive and, yes, the hamster balls.

The creatures were priced at $10 to $15 when they first hit the shelves in August. But a quick tour around Craigslist and eBay found the furry toys — Pip Squeak, Mr. Squiggles, Chunk and Num Nums — going for up to $50 a pop in Montreal and Toronto.

Besides the accessories, the hamster craze seems driven by the fact that parents can't get their hands on one, said Johnson, adding that when something is hard to obtain, people want it more.

Zhu Zhu Pets are aimed at the three-to-10-year-old crowd. Unlike past frantic-demand toys made by large manufacturers like Mattel's Tickle Me Elmo, Zhu Zhu Pets are made by tiny Cepia Inc. of St. Louis, with 16 employees in the U.S. and 30 in China.

Just six years old, Cepia previously worked on an electronic dispensing device for consumer products before turning to toys. Its only other product is a line of light-up bears called Glo-E Bears.

The company was started by toy industry veteran Russ Hornsby, 56, and the success of Zhu Zhu Pets wasn't entirely accidental. Hornsby was inspired to create a hamster prototype after seeing the success of toys like the classic barking puppy that flips. Stores in Phoenix, Ariz., were used as a test market in May.

The company got the word out with a mix of local cable ads and parties thrown by "mommy bloggers."

Hornsby said he was hoping to sell three to four pets per store per week, but was secretly hoping for eight. The result was exponentially higher.

"The rate was so astonishing everybody had to go back and pinch themselves," Hornsby said. Toys "R" Us pulled all of the test data to make sure it wasn't being manipulated, Hornsby said.

That gave a running start to Cepia's national rollout in August.

A Facebook fan site tracks parents' searches for the toys. Hornsby said he recently got a call at 4 a.m. on his cellphone from a mom asking for hamsters.

Calls have also been received at the store's Chinese base from parents trying to go to the source.

"They're calling because they're upset and they feel we're not doing a good enough job getting merchandise on the shelves," Hornsby said.

But with retailers being extra cautious on orders following the dismal holiday shopping season last year, the maker has had to scramble to catch up to demand.

Toy analyst Jim Silver at Timetoplaymag.com said it was late fall by the time Cepia and retailers realized how popular the toys were, and by that time it was difficult to increase production.

"You can't just go to China and flip a switch," he said. But in the past three months, the company has added three more factories in China.