Tent caterpillars live as groups in nests constructed from silk. A group of tent caterpillars can construct a nest of webbing that provides more protection than a single caterpillar on its own can produce. Tent caterpillars lounge in their nest all day when predators such as birds are about and emerge at night to feed. As dawn approaches, the caterpillars must find their way back to their nest. Caterpillars have poor vision and must rely on other means to find their way home.
Tent caterpillars deposit silk threads as they travel away from the nest. They can simply follow the thread when they need to return home. Ftizgerald and Edgerly* reported that tent caterpillars mark their silk trails with chemicals. When a caterpillar returns to its nest from a particularly good food source, it lowers the last segment of its abdomen onto the silk thread and deposits a chemical odor. Trails that lead to the best food receive the most chemical reinforcement. When a caterpillar leaves its nest the next morining, it can return to a prime feeding site. The scent allows the caterpillar to find food more quickly and spend more time feeding and less time searching.
*Fitzgerald and Edgerly, SITE OF SECRETION OF THE TRAIL MARKER OF THE EASTERN TENT CATERPILLAR. JOURNAL OF CHEMICAL ECOLOGY. Volume 8, Number 1 (1982), 31-39, DOI: 10.1007/BF00984003