5 things you probably didn't know about 'Rats' (via Morgan Spurlock)

Patrick Ryan
Morgan Spurlock's 'Rats' explores infestation on a global scale.

If you thought Pizza Rat was cute, then you clearly haven't met his family.

Gonzo filmmaker Morgan Spurlock (Super Size Me) introduces them in his nightmarish new documentary Rats, airing on Discovery (Saturday, 9 ET/PT) and Animal Planet (Oct. 30, 9 ET/PT). Adapted from Robert Sullivan's 2004 book Rats: Observations on the History & Habitat of the City's Most Unwanted Inhabitants, the real-life horror film shows how people deal with infestations on a global scale.

Spurlock shares five things you'll learn about the creepy critters:

1. Rodents are big business in Cambodia. In the country's Kandal Province, traders buy up hundreds of rats from local farmers daily and transport them over the border into neighboring Vietnam. There, they sell them to restaurants at considerably higher prices. "There are rats in Vietnam, but they just won't eat them," Spurlock says. "The fear is that since they're city rats, they'll have more disease in them. These are free-range country rats," which are considered safer to eat.

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2. There's an ancient Indian temple just for rats. More than 35,000 rodents scurry through the halls of the Karni Mata Temple in Rajasthan, India, also known as the Temple of Rats. Hundreds of people pour in daily to worship the rats, which many followers of Hinduism believe to be reincarnated members of their families. Visitors "actually try to feed and play with them, and eat the same food and drink the same milk that they drink," Spurlock says. "In their mind, this animal is one of their ancestors and they will ultimately become them again."

A famous Hindi temple in Rajasthan, India, is dedicated to the goddess Karni Mata and overrun by rats.

3. Terriers are effective vermin control in England. One of the documentary's most memorable scenes is set in Cheltenham, where 22 seemingly cuddly terriers routinely go on vicious hunts across the countryside. Their owner "gets hired by these farms to show up with these dogs, dig for rats and let the dogs kill them," Spurlock says. A lot of farms poison rats, who "have become so immune that other animals will eat (rodents) and then die as a result. So anything they can do to avoid putting poison on the farm, they'll do."

Terriers rip rats to shreds in the English countryside.

4. Rats carry more harmful parasites than you think. Leptospirosis, hantavirus and tapeworms are just three of the many infections that rodents can pass to humans through their urine, feces or bites. Another is the botfly larva, which is studied by Tulane University researchers in one of the film's most stomach-churning scenes. "The fly will land on a rat, lay the egg and then the egg will bore into the skin, basically feeding off you as it grows," Spurlock says. "Then it'll push its way out of your skin or the rat's skin and become a fly. To see that in person is really disturbing."

Scientists dissect rats in New Orleans to study the diseases they carry.

5. You can take "rodent management" classes in New York. The city hosts a program called the Rodent Academy,  which teaches homeowners, exterminators and food-safety personnel effective methods of fighting rat infestation. "To see how much historical smarts go into the education of exterminators today is something people are going to be really surprised by," Spurlock says. And with the city's rat population estimated at 2 million, "you start to get a sense that they are in every area of New York. When (we) put the camera under the sidewalk, and you see them all hiding there, waiting to come out, it's frightening."