Damage to the amygdalas may make a pearson fearless. Gleb Shumyatsky's lab reported in an article in Cell (2005) that knock out mice [mice lacking a specific gene] lacking the gene for stathmin were fearless. Stathmin is only transcribed and translated in the amygdalas, and the protein plays a role in microtubule formation. These fearless mice ventured into open areas and onto high platforms which normal mice avoid, because it exposes them to predators. They also failed to learn fear in classical conditioning experiments. If normal mice heterozygous for the fearless allele produce eight pups what number should be fearless?