A few meters away, two workers were carrying a member of the sensor caste, a being whose immense flattened head was attached to an atrophied body that was mostly lungs. The sensor had great platelike eyes, and its furred chitin sprouted long coiled antennae that twitched feebly as the workers bore it along. The workers clung to the hollowed rock of the chamber walls with hooked and suckered feet.

A paddle-limbed monster with a hairless, faceless head came sculling past them, through the warm reeking air. The front of its head was a nightmare of sharp grinding jaws and blunt armored acid spouts. "A tunneler," Mirny said. "It can take us deeper into the Nest -- come with me." She launched herself toward it and took a handhold on its furry, segmented back. Afriel followed her, joined by the two immature springtails, who clung to the thing's hide with their fore-limbs. Afriel shuddered at the warm, greasy feel of its rank, damp fur. It continued to scull through the air, its eight fringed paddle feet catching the air like wings.

"There must be thousands of them," Afriel said.

"I said a hundred thousand in my last report, but that was before I had fully explored the Nest. Even now there are long stretches I haven't seen. They must number close to a quarter of a million. This asteroid is about the size of the Mechanists' biggest base -- Ceres. It still has rich veins of carbonaceous material. It's far from mined out."

Afriel closed his eyes. If he was to lose his goggles, he would have to feel his way, blind, through these teeming, twitching, wriggling thousands. "The population's still expanding, then?"

"Definitely," she said. "In fact, the colony will launch a mating swarm soon. There are three dozen male and female alates in the chambers near the Queen. Once they're launched, they'll mate and start new Nests. I'll take you to see them presently." She hesitated. "We're entering one