But how do the ants "dismantle" the bridge? How do the last ants cross the gap? When and why do they start to break the bridge apart? Or are the last ants sim

But how do the ants "dismantle" the bridge? How do the last ants cross the gap? When and why do they start to break the bridge apart? Or are the last ants simply left alone to find another way to catch up with the colony?