The caterpillar who chances to be at the head of the procession dribbles his thread without ceasing and fixes it on the path which his fickle preferences cause him to take.

The thread is so tiny that the eye, though armed with a magnifying-glass, suspects it rather than sees it.
But a second caterpillar steps on the slender foot-board and doubles it with his thread; a third trebles it; and all the others, however many there be, add the sticky spray from their spinnerets, so much so that, when the procession has marched by, there remains, as a record of its passing, a narrow white ribbon whose dazzling whiteness shimmers in the sun.

Very much more sumptuous than ours, their system of road-making consists in upholstering with silk instead of macadamizing.

We sprinkle our roads with broken stones and level them by the pressure of a heavy steam-roller; they lay over their paths a soft satin rail, a work of general interest to which each contributes his thread.
What is the use of all this luxury?
Could they not, like other caterpillars, walk about without these costly preparations?
I see two reasons for their mode of progression.

It is night when the Processionaries sally forth to browse upon the pine-leaves.