Weather myths

Dear Tom,
We found a green fuzzy caterpillar in late July, the earliest we have ever
seen that kind before. Does this mean an early winter, or is it just a myth?
Dan Gazdziak, Chicago
Dear Dan,
It's an enduring myth. Your question is similar to many that we receive
concerning the ability of animals to predict the weather. There is no
documented evidence that robins or groundhogs (the usual suspects) -- or any
animals, including green fuzzy caterpillars -- have that ability.
Animal behavior, even when uncharacteristic or unusual, is a response to
past or current weather or the result of instinctive imperatives; it is not
based on predictive ability. That goes for plants, too. An exceptionally
great production of seeds, as with oak trees and acorns, or premature leaf
coloring in the autumn always result from past weather conditions or other
environmental factors, not from predictive ability.