He's taking her a little more seriously now, sitting up just a little straighter. The description of the city as both organic and a food chain is dead on. The squelch of the earth beneath his sneakers, the constant fight not to be the bottom rung of the food chain. Yeah, he can see that. Can feel that description like a sense memory.
"Huh," he says, and turns his laptop toward her to show her the trophic pyramid that's part of his reading. "Snap." It's not really; she's being metaphorical, but still, pretty funny co-incidence there.