"The ship doesn't want us dead. She gives off Kandrona rays in a few places." Okay, Marco didn't actually know how, or if, Stacy intended to feed the Yeerks. And it was probably too much to hope that she wasn't going to feed them at all.

Either way, Marco needed to at least give a reason for why he, supposedly a Yeerk, wasn't dead. So he'd made something up.

"Remember where you woke up? That's just the beginning. There's thousands of people stored there, maybe more. The ship claims that when the universes were being destroyed, she saved people with significant "stories". Important people. But she brought their families as well. And as I know of at least one person who has other family members here, this seems to be true. Since you're here, it's logical to assume that she brought your host's family as well."