Random samples of German cockroaches, the common household variety, have turned up some that are resistant to almost all known insecticides, including DDT.

FORBES: Digital Rules

In fact, it has long been known that exit polls, though they may claim to be based on random samples, suffer from biases in the way that they are conducted.

ECONOMIST: How to detect voting fiddles

U.S. Department of Agriculture inspectors are stationed at every U.S. meatpacking plant, where they look for signs of illness upon entry, conduct random samples to detect whether the meat contains antibiotics and where they inspect the organs and skin of the slaughtered pigs for disease.

WSJ: What China Can Learn From America's Hot Dogs

At random intervals during the tour, Gegenbauer stops for a tasting, dropping tiny samples of the balsamic and fruit vinegars onto the tongues of his guests using a pipette.

BBC: In the kitchen with Viennese history

Pose the following questions to help groups determine their polling samples and how their polls will be conducted: Will you use a random sample of voters or some other kind of sample?

CNN: Student News Learning Activity: Polling