Most maggots are very fussy and only eat dead flesh, so they're not a problem for their host. They can actually help to clean the wounds that they hatch into. In a pinch, doctors still use maggots to sterilize the wounds of soldiers.
But screwworms - screwfly maggots - are another matter. They are born ravenous, and they consume everything they can get their teeth into. As they devour the animal's healthy flesh, the wound gets bigger, luring more screwflies to come and lay their eggs. Those eggs hatch, and the wound gets even bigger...
Eww. Yuck. Repeat.
At the end of this cycle is a painful death for many a howler monkey.
But screwflies also bring a message of peace.
Like all primates, howler monkeys want mates, food, and territory - all the stuff that makes being a howler monkey fun. So they compete with one another for these resources - in other words, they get into fights.
But no matter how angry they get, howler monkeys never use their teeth or claws. Even if one of the monkeys is much bigger, all it ever does is slap the other one around and (of course) howl a lot.
You see, it's just not worth it to get into a real fight. Because even if the smaller monkey gets its monkey ass totally kicked, all it has to do is get in one tiny scratch, and the fight becomes a lose-lose proposition. One little scratch, after all, is all a screwfly needs to lay its eggs inside you.
Many scientists believe that the howler monkeys developed their awesome howling ability because of screwworms. Any monkeys who resolved their conflicts by scratching and biting (and getting bitten and scratched in return) were eaten from within by screwworms. Game over for all the scratchy and bitey howler monkey genes.
Eventually, all that was left in the jungle were non-scratchy monkeys. Survival of the fittest, which in this case were the non-scratchiest.
But there were still mates and bananas to be fought over, so the non-scratchy monkeys evolved a non-scratchy way to compete: howling. Survival of the loudest. And that's how we got howler monkeys.
See? Parasites aren't all bad. They take primates who otherwise might be killing one another and leave them merely yelling.
Chapter 11
MAJOR REVELATION INCIDENT
"What are you doing down here?" I yelled.
"What are you doing down here?" Lace yelled back, grabbing two blind fistfuls of my hazmat suit in the darkness. "Where the hell are we anyway? Were those rats?"
"Yes, those were rats!"
She started hopping. "Crap! I thought so. Why did it go all dark?"
"I kind of dropped my flashlight."
"Dude! Let's get out of here!"
We did. I could see only leftover streaks etched into my retinas by the flashlight, but Lace's eyes weren't as sensitive as mine. She pulled me stumbling back up the stairs, and as we squished through the poisoned-peanut-butter hallway, my vision began to return - light was pouring in from the health club through the open locker door.
Lace squeezed out, and I followed, slamming the locker shut behind me. Fluorescents buzzed overhead, and the basement looked shockingly normal.
"What was that down there?" Lace cried.
"Wait a second." I pulled her away from the security cameras and over to a row of weight benches. Sitting down, I tried to blink away the spots on my vision. Lace stayed standing, eyes wide, nervously shifting from one foot to the other.
"What the hell?" was all she could say.
I stared at her, half blind and still astonished by her sudden appearance. Then I remembered the doorman setting the elevator's controls, leaving them unlocked so that I could return to the ground floor.
I hadn't paid close enough attention. It was all my fault. I'd blown the first rule of every Night Watch investigation: Secure the site. But I was positive I'd closed the locker door behind me...
"How did you get down here?" I sputtered. "I thought the health club was closed at night!"
"Dude, you think I came down here to exercise?" She was still shifting from foot to foot. "I was headed out and Manny said, 'You know that guy you came in with this afternoon? He's here spraying for rats.' And I'm like, 'What?' And he's like, 'Yeah, did you know he was an exterminator? He's down in the health club right now, looking to kill some rats!' " Lace spread her open palms wide. "But you told me you were looking for Morgan. So what the hell?"
I didn't answer, just sighed.
"And when I came down here," she continued in a breathless rush, "the lights weren't even on. I thought Manny had lost his mind or something. But when the elevator closed behind me, it was totally dark." She pointed. "Except suddenly that locker was doing this ... glowing thing."
I groaned. On its killer setting, my Night Watch flashlight had been visible from up here.
Still hyperventilating, Lace continued. "And there was a hidden hallway, and the floor was covered with weird goo, and there were stairs at the end, with this insane squeaky pandemonium coming up from below. I called your name, but all I heard was rats!"
"And that made you want to go down the stairs?" I asked.
"No!" Lace cried. "But by then I figured you were down here, somewhere, maybe in trouble."
My eyes widened. "You came down to help me?"
"Dude, things didn't look so good down there."
I couldn't argue with that. No one else could have messed this up quite as totally as I had. Things were bad enough, with a great big rat reservoir bubbling up from the Underworld, along with a weird peeplike cat and something big enough to make the earth shudder. And right smack in the middle of it all, I'd managed to insert Lace - a Major Revelation Incident.
I was screwed. But I found myself staring at Lace with admiration.
"All those rats..." A note of exhaustion crept into her voice as hysteria subsided. "Do you think they'll follow us?"
"No." I pointed at her shoe. "That stuff will stop them."
"What the ...?" She stood on one foot, staring at the bottom of her other shoe. "What the hell is this crap anyway?"
"Watch out! It's poisonous!"
She sniffed the air. "It smells like peanut butter."
"It's poisonous peanut butter!"
She let out a sigh. "Whatever - I wasn't going to eat it. Note to Cal: I do not eat stuff off my shoe."
"Right. But it's dangerous!"