Hubbard could see the old man was thinking ahead to tracking down the source of the invasion. “Possibly, but not necessarily very big,” he replied. “These cockroaches might live in layers on top of each other. That’s not typical of cockroaches and I could be wrong, but we needn’t necessarily look for a terribly large nest.” He stopped and turned to Elizabeth. “Last night, you did tell me about some kettle holes on the island. We should certainly look into that.”

Before Elizabeth could respond, Amos Tarbell was inquiring, “Would these cockroaches have something like a queen bee, then?”

Hubbard nodded. “Probably more like termites, who have a king and queen—if there’s a central nest at all,” he cautioned.

Johnson remained alert and inquisitive. “Okay, we know how fish school together, and the way sharks can sense vibrations a long way, and how dolphins and whales actually talk to each other. But how in Old Scratch can bugs do all the communicating you’re talking about?”

Elizabeth said at once, “Everyone who’s seen the roaches says something about their hissing noises. Could that be it?”

Hubbard shook his head. “In the species that we know do hiss—like the Madagascar roaches—it’s a sign of disturbance. Actually, it’s more a puffing of air out of their bodies through the spiracles, certainly not the kind of communication the captain is asking about.” Hubbard stepped back. “That’s another of Dr. Lindstrom’s fields.”

Wanda Lindstrom picked up at once, explaining, “A main way these roaches could be contacting each other would be through some specific chemicals we call phero­mones.” She pronounced the last word slowly—“pher-­o-­mones.” It was a key to their understanding of what must otherwise be incomprehensible. She saw they were all attention. She could wish her college students were always as alert. But then, students’ lives and livelihoods were not at stake . . .

“Pheromones are absolutely basic to insect communication in cases of species social grouping,” she resumed. “Mostly, the chemicals travel through the air as odors. They can be very specific. For example, one chemical pheromone can be the signal for food, another for danger, and so on. Among the termites, interestingly enough, the queen and king of a nest produce a substance that inhibits reproduction by the other insects of the group. In this way, the royal couple maintains solid control of the generations—Nature’s way of continuing the specific characteristics it apparently wants to go on.”

“Interesting kind of dictatorship,” Reed Brockshaw mentioned.

“Nature doesn’t provide many models of democracy,” Hubbard commented blandly.

His observation brought to Elizabeth’s mind a Churchill quote from her political science course: “Democracy is the worst of all systems, except for the alternatives . . .” It seemed true in the animal kingdom as well!

Wanda Lindstrom underscored, “The pheromones are a key method of controlling and maintaining the specialization the colony requires—the workers, the nurses, and so on.