What tricks can I play upon them?
I see only two: to do away with the leader; and to cut the thread.
The suppression of the leader of the file produces nothing striking.

If the thing is done without creating a disturbance, the procession does not alter its ways at all.

The second caterpillar, promoted to captain, knows the duties of his rank off-hand: he selects and leads, or rather he hesitates and gropes.
The breaking of the silk ribbon is not very important either.

I remove a caterpillar from the middle of the file.

With my scissors, so as not to cause a commotion in the ranks, I cut the piece of ribbon on which he stood and clear away every thread of it.