Menu
Share
 
Switch to Desktop Site

Insect swarms

Image

Image 6 of 12

 

Each year, tens of millions of Monarch butterflies travel more than 2,800 miles from Canada and the United States to spend the winter in the forests of Michoacan in the volcanic highlands of Mexico. For scientists, this unique migration is an enigma of nature.

PHOTO: Sipa/Newscom/File

Next Image Previous Image

Image 6 of 12

 
About these ads

Share