10 monarch butterfly questions answered

We get a lot of questions at the Dickinson County Nature Center, and a lot of them have to do with butterflies and bees.

Let's take a look at some of our most commonly asked questions about monarch butterflies.

How long do monarch butterflies live?

A monarch is in the egg stage for three-five days, is a caterpillar 10-14 days, is in chrysalis 10-14 days and lives two-six weeks as an adult. (Read about the life cycle here) Fall monarchs are different, because they live about six months. These butterflies do not reproduce right away but instead fly south to Mexico, overwinter and then are the first generation of the next year to fly north.

It can take four-six generations of monarch to make their way all the way to the northern most breeding grounds in the Midwest or southern Canada before the final generation migrates back south to Mexico for the winter. So when you see monarchs this spring, they are not the same monarchs that flew south last year. They are that monarch’s great-great-grandchild at least!

How many eggs does a female monarch lay?

A summertime female monarch lays eggs during her two-six week lifespan, laying probably 300-400 eggs in the wild.

Are monarchs poisonous?

Many predators don't like to eat monarchs. Since monarch caterpillars survive off of milkweed, they store toxins from the plants. These toxins make caterpillars and adult monarchs distasteful to most predators, although some have adaptations that allow them to tolerate these toxins.

Viceroys mimic monarch butterflies because monarchs are so distasteful to predators. It allows viceroys to get away when they are mistaken for their look-alike.

(How to tell apart four orange-and-black butterflies)

Do monarchs sleep?

Monarch butterflies are diurnal, which means they are active during the day. They need a body temperature of 84 degrees to be able to fly, and the sun also helps them find their way. At night, butterflies find a place to roost in trees or shrubs. They don't technically sleep, at least the way humans do, but they rest in a state called torpor.

Does it hurt a butterfly to pick it up?

We rear and release monarch butterflies in Pollinator Paradise each summer, and we also have a public tagging event during the annual Bee & Butterfly Festival. That means that we do end up handling butterflies quite often.

Butterflies can be injured when touched, because they are covered in feathery scales that can easily fall off. To hold a butterfly, we use the thumb and forefinger to gently grasp all four of its wings and make sure not to rub them against each other so the scales aren't harmed.

Do monarchs return to the same area every year?

Since it takes four-six generations of monarchs to complete migration each year, it is never the same monarch coming back to a spot. However, monarchs often do return to the same area, sometimes roosting in the same tree each year. There doesn't appear to be a specific reason for this. Perhaps it is just great habitat or the perfect stopping point.

Why is a monarch caterpillar eating my dill/parsley?

It is not a monarch! Monarch butterflies only lay eggs on milkweed species, and caterpillars only eat milkweed species. That's is what makes milkweed the monarch's host plant.

However, swallowtail caterpillars look similar to monarch caterpillars --- they are both black, white and yellow --- and swallowtails feed on anything in the Apiaceae family, which includes parsley, Queen Anne's lace, carrots, celery, fennel and dill.

(See the differences between monarchs and swallowtails here)

How do you tell the difference between a male/female monarch?

A male monarch butterfly has thinner black veins and a black spot on each hind wing. Female monarch butterflies lack the black spot and have much thicker black veins.

male markings on a monarch

Male monarch butterfly

male marking absent to show it is female

Female monarch

Why are monarch butterfly populations struggling?

Milkweed was misunderstood for many years and was thought of as a weed, so people attempted to eradicate it. Once it was more understood that monarchs must have milkweed to survive, efforts have increased to try to replant milkweed throughout Iowa and the rest of North America.

In addition to their host plant, monarch butterflies and other pollinators also need native food sources for adults. That means nectar sources such as purple coneflowers, goldenrod, Joe pye weed and other prairie flowers.

Pesticide use has also damaged many pollinator populations, and neonictinoids have been proven to stay in soil and plants for years after use. Unnecessary fertilizer and pesticide use has harmed pollinators such as monarchs.

How can I help monarch populations?

  1. Plant natives! There are plenty of milkweed varieties, read about them here, that are beneficial and also beautiful in landscaping.
  2. Cut down on pesticide use. Neonictinoids are considered harmful to pollinators, and many other chemicals that have widespread usage are not only deadly to bugs people don’t want around but they are deadly to everything. That means chemicals that kill mosquitoes also kill pollinating bees, butterflies, moths, beetles, ants and other beneficial insects.
  3. Get involved. Monarch Watch is asking for citizen scientists to keep track of monarch butterfly numbers throughout the country to help more accurately identify populations. You can sign up to count butterflies in your own community. Find out more about that here.
  4. Advocate. Make sure to talk to your friends, your neighbors, your family about the importance of pollinators and taking small steps in our own yards that will help bring back our populations.


  1. Jill on July 29, 2019 at 8:49 am

    I saw a butterfly carrying a bug from my mimosa tree down to the ground. At first I thought the butterfly was dying and was cascading gently to the ground. But upon further investigation it was carrying something that looked like a bee. Has anyone else seen this behavior and what is the butterfly doing? I have witnessed this several times and it is the same type of bug that eventually the butterfly releases in the grass and both fly off.

    • Brenda Jones on February 5, 2020 at 10:21 am

      Why do some Monarch Butterfly’s Kill other Monarch Butterfly’s. I’ve seen it happen more than once ?

      • kiley on February 5, 2020 at 10:28 am

        We’ve never seen this before — it possibly could have been a territorial squabble between two males? Caterpillars will be cannibalistic if food is scarce, but adults doing harm to each other would be rather rare.