She wanted to know where they were going in such a hurry, and whether their abrupt pauses and frantically waving antennae had some hidden significance. Later she came to realize that the ants followed invisible trails across the floo
Ants leave trails of home-finding pheromone when looking for food and food-finding pheromones when returning home. This can cause the paths to be longer than the most sufficient trail. https://www.uky.edu/Ag/Entomology/ythfacts/allyr/ants.htm