something that has been irking me since i've heard it is that exchange between Lizzy and Riley about the Sweat Bottle Experiment and the playback video they watched. (Chapter 7 Pt 2)

the two women are watching what Lizzy had filmed...
and Riley says: "Stop! Right here, Look! They're drooling--like dogs."
Lizzy: "They do that; their hungry."
R: "Not like this, they're dripping onto the ground. I had a dog once who i didn't neuter and he did the same thing when he was around another dog in heat."
L: "It's something like the musk. Zombies and sex don't seem to go together, if you ask me."
R: "Sweat makes pheromones, and those bottles were filled with them, male and female. Attraction starts with their nose and seems to end with their teeth."

so what of it? is this just a passing conclusion or is there more to it? Do zombies revert to basic animal instinct? if they aren't hungry (at the time), then biting them is a result of a desire/need/instinct to Pro-Create?
(maybe their zombie 'bits' don't function anymore? sorry for the crassness)

if this is nothing new, i get it. it's not a 'game changer' but it has been bugging me how it was seemingly glossed over. but i can understand it just being the cause of the success of the sweat jars and nothing more.