I think I- he probably disturbed them. He thought he'd found a cluster of crystals that could've bought years worth of food. He'd dug them out all the way down to what he thought was a weird rock they were embedded in. If the Nation Eater they were attached to was already hunting, it would've revealed itself sooner.

[There's a mental shudder]

Even then it just pushed him back at first. Almost gentle about it. It was strange.