My favorite bike training ride goes through a portion of the White Mountains National Forest on the Maine-New Hampshire border. As you enter the forest you’ll see reminders about not bringing in firewood from outside of the area. The reason for the reminders is to prevent the spread of invasive insects that can damage the ecosystem. As is explained in this new National Geographic 101 video, invasive insects, plants, fish, and other animals can all wreak havoc on an ecosystem.

Last year TED-Ed published a lesson about invasive species. The Threat of Invasive Species explains the problems caused when plants and animals are introduced to non-native habitats. The lesson explains how plants and animals get introduced to new environments, what happens when they are introduced to those environments, and what some governments do to try to control invasive species.