AUTHOR: Scott Westerfeld

PUBLISHER: Penguin Group

PUBLICATION DATE: Februrary 8th, 2005

Two days after arriving in New York for college, Cal loses his virginity to a girl who picks him up. From this encounter Cal picks up an STD, but this is an unusual one: it turns its victims into "peeps" -- parasite positives—raving cannibalistic monsters with unusual strength, night vision, heightened senses, and an affinity with rats. Cal himself turns out to be immune, but he's a carrier—he gets the strength and senses without the nasty side effects. But before he knows it he has infected others.
Cal is recruited by the Night Watch, a secret government organization that has existed for centuries to contain the disease and its victims. His first assignment is to capture all the girls he's infected. But soon Cal realizes that there is more going on than he has been told: the disease is changing in response to mysterious forces from under the earth that are waking up after centuries of slumber.

The science in Peeps is all about parasites and how they can change how animals act, feel, look. It is also about how parasites move from animal to animal and how they evolve to become different strains that can infect to other animals. The book is set out in an interesting manner in which the odd chapters tell the story of Cal Thompson but the even chapters give information on different parasites and how they effect the animals that they do.


Dicrocoelium dendriticum or Lancet liver Flukes live in the stomachs of grazing mammals. for example a cow or hare

Here is a YouTube video to explain how lancet liver flukes get around and control their Hosts.

Hairworms or Nematorpha (2)

Scientists have long argued whether strange behavior in parasite-infested animals is deliberately engineered or simply an accidental side effect. They now have a new study that backs up the first option, being deliberately engineered. These are: Nematorpha or Hairworms.
Nematomorpha.gifHairworms, which live inside grasshoppers, force the hosts to commit suicide by jumping into water, when they are ready to mate they pump the grasshopper full of chemicals and sabotage their central nervous system which muddles its brain,driving the grasshopper to water. The Hairworm comes out the rear end of the grasshopper to find a mate and continue its life cycle.By this time the Hairworm occupies most of the hosts body cavity, except for the head and legs, its is approximately four times longer than the grasshopper it was living in. The team that discovered this in 2005 think that their findings may help the development of new medical treatments as parasites that cause rabies, sleeping sickness, and toxoplasmosis may manipulate their victim in similar ways.

If you want to see a video about what the scientific team saw:
its in french by the way


Toxoplasma gondii is a single-celled parasite that causes Toxoplasmosis (toxo), it is very common as more than 60 million people in the U.S.A alone have it although most of them don't know it. These people dont know they have it because the immune system generally keeps the parasite from causing illness. But in some cases as those with inherited immune defect, AIDS, body-wide chemotherapy and babies will find that they will get the symptoms which are like those for a fever.
In people who do have the above immune defects, an infection that occurs any time in life can lead to damage to the eye, brain and other organs. When the eye is effected it can lead to reduced vision, blurred vision, pain (often with bright light), redness of the eye, and sometimes tearing.
Toxoplasma gondii can be contracted by touching your hands to your mouth after gardening, cleaning a cats litter box or anything else in which your hands might come into contact with cat feces. It can also be contracted by eating raw or partially cooked meat (mainly pork, veal or lamb) or touching your hands to your mouth after touching raw meat.
At the University of Oxford they tested the hypothesis that the parasite Toxoplasma gondii manipulates the behaviour of its rat host in order to increase the cahnce of it getting eaten by a cat, which is the final host in the Toxoplasma life cycle, meaning that the Toxoplasma parasite has altered the brain in its favour. To find out more about this examination go to :

Leucochloridium paradoxum (4)

This little thing is a parasite which can change what its host looks like. They live inside snails and birds.

They change the colour of the snails antennae to attract the birds.

If you don't believe me WATCH THIS VIDEO!!!!!



These little fiends have the ability to stifle the 'alarms' that get set off in their hosts (insects) bodies, allowing them to get on with their dirty work. They revamp the insects reproductive system, with freakish results- an apparent anti-male agenda. The males are transgendered into fertile females, or killed. No fathers are needed for infected virgin females to give birth and the sperm of infected males will fail to impregnate uninfected females. This happens because Wolbachia can live in eggs but not sperm, so only infected females can pass the bacteria to offspring.

All this genetic fiddling has given these parasites an advantage among other parasites: Wolbachia can reproduce without killing their hosts, so the bacteria have a better chance of spreading, right now they live in approximately 70 percent of all arthropods. This doesn't mean they always get it right. Sometimes the bacteria can't always finish the job, resulting in part male, part female offspring.

This is a Wolbachia infested drosophila embryo imaged by confocal microscopy.




James Owen

for National Geographic News
September 1, 2005




Christine Dell'Amore
National Geographic News
Published January 26, 2010