Most interesting, she said. Well, most people find the least humanoid kind of aliens to be fascinating, so he can immediately think of one species that fits the bill. "About fifteen years ago, a Federation mining colony on Janus Six started running across tunnels through solid rock that were too smooth to be naturally formed, and apparently made with corrosive acid. The deeper underground they went, the more tunnels there were, until they stumbled across living rock creatures about this big," he says, using a hand to indicate the height of a small pony, or perhaps a very large dog.

"The miners thought they were some kind of monster, or just really weird animals, but no one had ever encountered silicon-based life, so it got the attention of the scientific community. A small Vulcan science ship came to study them, which was tough since the creatures kept tunneling away whenever anyone got close. One of the scientists used synthesized gemstones to lure one in and mind-melded with it - that's a touch-telepathy thing - and found out they were sentient, and called themselves the Horta. They'd been just as wary of us carbon-based lifeforms since they'd never seen anything like us before, so they were just as surprised to find out we were intelligent."