Shiver to Warm Their Muscles
The most obvious thing you'd see on a cold day in a colony would
be this: The forest floor would be alive with shivering monarchs.
The butterflies move their wings so quickly they are blurry. You
can even hear their wings as they flutter against nearby leaves.
shiver to warm their muscles. After shivering, monarchs can crawl
and fly at temperatures that would otherwise be too cold.
© Journey North