Zhu Zhu Pets™ name.

Anyone know if the name is actually Mandarin, and if so what characters? I know they're made in China but that doesn't mean anything, as nearly all toys are made in China now. They used to be called Go Go Pets™, and in some markets they apparently still are, but while their blog's oldest post asks "Why did Go Go Pets™ become Zhu Zhu Pets™?" they don't say why, or what the name comes from.

The manufacturer's site (warning, annoying intro page, complete with music) says nothing about where the name came from. Perhaps they're too busy turning them out by the hundreds of thousands (CEPIA Produces 220,000 Zhu Zhu Pets Per Day And They Are Still Out Of Stock) to put something up on the site.

The toy's site is equally annoying, but no more informative about the name.

Edit: Bloomberg did an article on them today, but nothing about the name either.