TOPSHAM — Bats, the only flying mammal, are super-important, yet terribly misunderstood.

On Tuesday, Oct. 29, scientist Trevor Peterson of Stantec Environmental Consulting will try to demystify them during a 6:30 p.m. presentation at Topsham Public Library.

As the sun sets, bats help humans by consuming up to 900 mosquitos an hour. Peterson has studied bat populations at the Cathance Preserve and throughout the Gulf of Maine and New England using acoustic monitoring devices.He’ll discuss the risks to this creature, and how local scientists and students keep a close eye on bat populations.

For more information about Cathance River Educational Alliance, visit www.creamaine.org.

Program like “Bats” are family friendly, free, and open to the public. They are held at the Topsham Public Library the last Tuesday of each month from 6:30-8 p.m.

Upcoming programs include:

— Winter Moth in Maine, Tuesday, Nov. 26. An invasive insect is here in Maine. What is the outlook, and why should people be concerned? Winter Moth presents a major risk to many fruit and hardwood trees. The program will be led by Charlene Donahue, chief forest entomologist who is responsible for the statewide forest insect surveys. Cosponsors include Topsham Public Library, Cathance River Education Alliance, the Brunswick Topsham Land Trust and the Maine Forest Service.