Do Monarchs Know Which Way to Fly?
Here’s what the biologists did: They collected monarchs, divided them into three groups, and put them under artificial light conditions in their lab.
The control group received light during normal daylight hours, but the two test groups were “clock-shifted.” They were exposed to 12 hours of light but not during normal daylight hours.
After 5 days, the butterflies were taken outside. Their flight direction was tested under normal daylight conditions. Which way do you think each group flew?