Both male and female bagworms make bags constructed from the plant material they are feeding on. This time of year, the male bags are empty. However, the female bags are full of eggs. To prevent damage next year, do your best to remove as many of the bags as possible. Make sure to throw these bags in the trash and not the compost. If you cut a bag open, male bags should have an empty pupal tube inside. Some gardeners report that female bags are often higher on the plant.