With the onset of the northeast monsoon (Thulavarsham), the forest of Aralam sees the natural phenomenon of butterfly migration. The phenomenon starts during October-December from the plains to the Ghats and will return to the plains during April-June, just before the advent of the southwest monsoon (Edavapathy). It is said that the migratory butterflies breed on the Ghats during the winter-summer periods and their progeny starts returning to the plains by April. This process helps the butterflies to avoid the intense monsoon conditions during their life cycle.