If you find a football-size (or larger), gray, papery structure attached to the branches of a tree or shrub, you’ve probably discovered the nest of a bald-faced hornet. (The only other hornets that build a similar nest are aerial hornets, and their nests usually have wider strips, and less of a scalloped appearance than those of bald-faced hornets.) This structure is actually a nursery, filled with several horizontal layers of hexagonal cells, in which eggs are laid and larvae are raised. These horizontal layers are surrounded by a multi-layered envelope, which, like the cells, is made of masticated wood fiber from weathered wood such as fence posts and hornet saliva. The different colors reflect the different sources of wood that have been used. Although only the queen bald-faced hornet survives over winter (in a rotting log or other protected spot), the workers do not die until freezing temperatures have really set in, so wait for another month before approaching a nest!