JERUSALEM (JTA) — Millions of butterflies are blanketing Israel during their annual migration to Europe.

Up to a billion butterflies known as Vanessa cardui, or painted lady, are passing through Israel in search of food on their way to their breeding grounds in Europe. They have been spotted in large numbers in the southern Arava region, across the Sharon Valley, and through major city centers up to the Carmel Mountain range, Israel Hayom reported, citing the Association of Butterflies in Israel.

It is reportedly the largest migration of such butterflies ever seen in Israel.

A survey sample showed that many thousands per hour of the butterfly species have been  seen migrating across the skies compared to just a few hundred in a similar event five years ago, according to the report, citing Noam Kirshenbaum of the association.

Butterfly sightings, which began last week, continued on Sunday.