Today’s Wonder of the Day was inspired by Nancy from AL. Nancy Wonders, “ What is the average life of a butterfly? ” Thanks for WONDERing with us, Nancy!

Why did the little boy throw butter out the window? He wanted to see the butterfly! OK…that’s an old joke. You’ve probably heard it many times. But who doesn’t like to see butterflies?

Butterflies fascinate many people. One reason is the miraculous transformation they go through. They start as caterpillars. Then, through an amazing process, they turn into beautiful butterflies.

One of the joys of sunny summer days is watching butterflies float around the backyard. As they flit from flower to flower, they seem so gentle. Would you believe, though, that butterflies can actually fly incredible distances?

One butterfly species—the Monarch butterfly—travels great distances every year. It does so to survive during the winter. Summer in North America is usually nice and warm. But Monarch butterflies can’t survive the cold winters of most parts of the United States.

Each year around October, Monarch butterflies migrate south and west. They do so to find warmer weather. Monarch butterflies from the Eastern United States travel to Mexico. Those that live west of the Rocky Mountains head to California.

Amazingly, Monarch butterflies travel to the same destinations every year. How long is the trip? For some Monarch butterflies, the journey can be as long as 2,000 miles. It could take up to two months to complete. Isn’t it cool that something so beautiful and delicate could travel so far?

The story doesn’t end there, though. It just gets better. The life span of Monarch butterflies is fairly short (6-8 weeks). That means it’s different generations that make the same trips each year.

Most insects do not migrate. That’s because their life spans are not long enough. Only Monarch butterflies born in September and October live long enough to migrate. The butterflies that travel to Mexico and California have children and sometimes grandchildren there. It’s those children and grandchildren that make the return trip in the spring.

How do they do it? Scientists believe they use a system called a time-adjusted sun compass. In other words, they follow the sun. Because the sun is always moving, though, this isn’t as easy as it sounds.

Monarch butterflies have a 24-hour internal clock that is part of their antennae. This part of the system tells the butterflies what time of day it is. Depending upon the time of day, the butterflies can then tell where the sun should be.

The butterflies then use special photoreceptors inside their eyes to follow the angle of the sun. Incredibly, Monarch butterflies can pass on these directions to their children. Isn’t nature WONDERful?