With autumn breezes putting a slight chill in the air, Indiana bats are starting to settle into their hibernacula, the caves at Sodalis Nature Preserve where they spend the winter. Interpreter Guide Gale Rublee will lead the hikes. She said chances are good that participants will see bats flying overhead at sunset. Female bats often enter hibernation shortly after arriving at the hibernacula, but males remain active until late autumn to breed with females arriving late. Most Indiana bats hibernate from October through April. Occasionally, Indiana bats are found hibernating singly, but almost all are found hibernating in dense clusters. The latest bat census at Sodalis Nature Preserve confirms its place as the country’s most important hibernation spot for Indiana bats, with an estimated 222,129, an 8.7 percent increase from the last survey two years ago. The full Night Hike program lasts about two hours and follows a 2-mile paved loop with a steep incline. Participants are welcome to stay with the group or return to the parking lot on their own. There is a strict limit to the number of participants and reservations must be made online at www.hannibalparks.org Rublee is a nationally certified interpreter guide with more than 25 years of experience in outdoor education.