Skip to main content
You are the owner of this article.
You have permission to edit this article.
Spread your science wings with these facts about monarch butterflies

Spread your science wings with these facts about monarch butterflies


Monarchs gather into groups called a bivouac at night.

See how much you know about monarch butterflies in this Q&A from the Monarch Joint Venture. Find more fascinating facts at Monarch Watch and the Xerces Society.

Q. Do monarchs return to the same areas when they are traveling north?

There is no evidence to suggest that an individual monarch’s offspring return annually to the habitats their ancestors came from. It is most likely that the monarchs you see each year are new to your garden, and not the same monarchs that grew there previously, or their descendants. This is because there are four generations that take place throughout the year for eastern monarchs. By the time monarchs are back in the summer breeding range the next year, they are generations removed from the breeding individuals of the previous year.

During the eastern population’s summer breeding season, three generations pass before the migratory generation (the fourth generation) leaves for Mexico. Successful migrating monarchs will live between six to nine months and reproduce and die in the southern United States in the spring. Their offspring then carry on their migration north.

Q. What do monarchs eat?

In North America, monarch caterpillars rely on milkweed (Asclepias genus) and a few closely related genera to grow and develop. Female monarchs use a series of cues to find milkweed and lay their eggs on the leaves of this plant. After an egg hatches, the caterpillar feeds on milkweed exclusively, and does not leave the host plant until it is ready to pupate. Therefore, milkweed is known as the “host plant” for monarchs. Adult monarchs drink the nectar of many species of flowering plants. It is important for monarch habitat to provide food sources for both caterpillars and adult butterflies.

Q. How many legs do monarchs have?

It sometimes looks like adult monarchs only have four legs, and that caterpillars have a lot more. However, all insects, including monarchs, actually have six legs. Adult monarchs hold their front two legs close up to their bodies most of the time, and can even use these two front legs to taste-test milkweed before laying eggs on it. Monarch caterpillars have six true legs (three sets) and 10 prolegs or false legs (five sets).

Q. How far can monarchs fly?

Every fall, North American monarchs fly south to spend the winter at roosting sites in Central Mexico or along the Pacific Coast. Monarchs are the only butterflies to make such a long, two-way migration. Eastern monarchs may fly up to 3,000 miles in the fall to reach their winter destination, if they are coming from the far northern part of the eastern breeding range.

Less is known about the timing and location of breeding and migratory movement in the western United States. Usually, monarchs coming from west of the Rockies make a shorter journey to the coast of California.

Q. Does it hurt monarchs to touch their wings?

Gentle handling of monarchs to test for OE (a parasite that infects butterflies) or tag, for example, is relatively harmless. Some wing scales are removed with handling, so it is important to minimize the amount you handle a butterfly to reduce the risk of damaging the wings. To hold a monarch butterfly safely, use your thumb and forefinger to firmly grasp all four of its wings. For instructions on OE sampling, visit Project Monarch Health’s website, For instructions on monarch tagging, visit

Q. Do monarchs sleep?

It depends what you consider sleep. Monarchs are active during the day, or diurnal, and they rest at night or when it is cool in trees, shrubs or other sheltered areas. This state of rest in most insects is called torpor. They do not have eyelids, so they rest with their eyes open. Monarchs are also unable to fly if it is below 55 F.

Q. Why do monarchs sit with their wings open?

Monarchs are gliders — they do not rapidly flap their wings like many other flying insects. Instead, they flap their wings a few times, and ride on columns of thermal (warm) air. Because of this, they’re able to fly very high. They’ve been reported as high as 1,250 meters, or three-fourths of a mile, above the Earth’s surface.

You could be seeing monarchs sitting with their wings open for a couple of reasons. Sometimes monarchs will sit with their wings open to heat up their flight muscles. It’s also very hard for monarchs to fly with wet wings. If a monarch gets wet in the rain, it may sit and dry its wings.

Q. What’s the difference between a chrysalis and a cocoon?

Cocoon and chrysalis are often used interchangeably when talking about monarchs and other butterflies. However, they are two completely different things. Cocoons are specific to moths, while chrysalises are formed by butterflies. Moths spin silk around themselves and molt inside the silk casing. This provides extra warmth and protection from the surrounding environment. You can usually find cocoons attached to the side of something or buried under ground or in leaf litter.

Chrysalises, on the other hand, are not silk. Butterflies molt into a chrysalis, which is a hard exoskeleton covering that protects the developing butterfly beneath. Chrysalises are typically found hanging from something. For example, monarchs spin a small silk button to hang upside down from before molting from head to abdomen.

Q. How do monarchs find milkweed?

Monarchs find milkweed using their sense of sight and smell (sensory receptors). They have sensory receptors in their antennae and front legs. Reproductive female monarchs continuously move across the landscape in search of milkweed on which to lay their eggs.

Q. How do monarchs travel such far distances?

Monarchs are able to travel such far distances because they fly very efficiently. They take advantage of air currents and actually soar, like many birds do. This takes much less energy than flapping their wings all the time. They choose altitudes at which they can take advantage of the wind to help them on their long migratory flights. And they don’t fly when there’s a strong wind blowing in the wrong direction. They also store up a lot of energy for these long trips. This energy comes from the food they eat as caterpillars, and also from the nectar they get from flowers.

Q. How are monarchs toxic to predators?

Monarchs become toxic to predators by sequestering or storing toxins from the milkweed plants they eat. Milkweed contains cardenolides, or cardiac glycosides, which are toxic to predators. This makes monarchs very distasteful or unpleasant to predators. Some predators have evolved ways to avoid or tolerate these toxins, such as the bird predators found in the Mexican overwintering colonies.

Q. Do monarchs live in other parts of the world besides North America?

Yes, monarchs are found in many places throughout the world, but they probably originated in the Americas, and were spread either with the help of humans or on their own to other places. They are found in Australia and New Zealand, and many islands east of these countries (most islands between Australia and Tahiti have monarchs). They are also found in Hawaii, most islands in the Caribbean and even sometimes in western Europe.

Photos: What to plant if you want to attract pollinators

Omaha World-Herald: Inspired Living

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.

Marjie is a writer for The World-Herald’s special sections and specialty publications, including Inspired Living Omaha, Wedding Essentials and Momaha Magazine. Follow her on Twitter @mduceyOWH. Phone: 402-444-1034.

Related to this story

Get up-to-the-minute news sent straight to your device.



Breaking News

Huskers Breaking News

News Alert