Henderson, Ky. Tags the size of a dot will be stuck on migrating butterflies Saturday by participants in a Monarch Migration Mystery field trip at the Sauerheber Wildlife Refuge.
The adhesive tags will help researchers at Kansas University studying the butterfly's annual trek south.
"It doesn't look like they're flying anywhere, that they're just fluttering around, but they actually have a course and a mission," said Brian Gasdorf, naturalist at the Audubon State Park.
Each fall beginning in late August, millions of monarch butterflies east of the Rocky Mountains migrate to Mexico. The butterflies then return the following spring to the United States.
Most butterflies have a lifespan of two or three weeks. But monarch butterflies can have lifespans of eight or nine months.
Instead of mating right away, their bodies prepare for the strenuous flight. They stop to consume nectar, cluster at night and by day conserve their fuel in flight by gliding on air currents.
Most of the monarchs that leave Mexico in March will be dead before they get out of the southern United States. Their offspring continue the journey back home, reproducing as they move northward.
The tag numbers from Saturday's event outside Henderson will be sent to KU.
That way, once volunteers catch the insects and record the numbers in Mexico, it will be possible to determine where the butterflies have been.