The Poisson distribution played a key role in experiments that had a historic role in the development of molecular biology. In particular, the interpretation and design of experiments elucidating the actions of bacteriophages and their host bacteria during the infection process were based on the parameters of the Poisson distribution. I briefly review three of the most important of these experiments and offer suggestions on the use of the Poisson distribution in statistical calculations in biology laboratory exercises reflecting the use of the Poisson distribution in current biological investigations.