“Monarchs have a biological clock in their brain, but also one
in their antennae that tells them when the sun rises and sets,”
Taylor said. By keeping track of the sun’s location in the sky,
these two body parts act like a calendar and compass for the
butterflies. Monarchs that spend the winter in Mexico live eight
or nine months, longer than any other monarchs. They begin their
migration in late summer or early fall and reach Mexico in late
fall and early winter, covering an average of 25 to 30 miles a
day (about the distance from Washington, D.C., to Annapolis,
Maryland). They begin their flight back to the southern United
States in late February and March. Along the way, each female
lays a few hundred eggs. As the migrating generation dies off a
month or two later, the new generation continues the springtime
migration north and reaches the eastern United States and Canada
in late spring and early summer. They have children and
grandchildren of their own, and the cycle continues. Migrating
monarchs face man