BAXTER — What started as a practical childhood science experiment birthed from classic grade school curricula, colorful life-cycle diagrams and the curiosity of Carrie Scarfino’s three children has turned into a yearly venture for the Baxter mom. “I started doing more research, and I realized how the monarch butterfly population has decreased significantly over the years,” Scarfino said. “I was like, OK, what can I do to help?” Carrie Scarfino i…