"Cootie Genetics" is a hands-on, inquiry-based activity that enables students to learn the Mendelian laws of inheritance and gain an understanding of genetics principles and terminology. The activity begins with two true-breeding Cooties of the same species that exhibit five observable trait differences. Students observe the retention or loss of traits among first-generation heterozygotes, hypothesize what happened to these traits, and design an experiment to test their hypotheses by mating the first-generation Cooties. With the second generation, Mendel's principles of segregation and independent assortment of alleles are observed; dominant and recessive traits and tools students need to construct Punnett squares are apparent.