Exhibits & Programs

Tropical Butterfly House.

Pacific Science Center’s Tropical Butterfly House opened Dec. 26, 1998. Our goal in creating this 4,000 square foot exhibit was to build an immersive exhibit that would provide a glimpse into a part of the world very unlike Seattle — a warm, sunny place where colorful butterflies are active 365 days a year. Seattle skies do not provide the light necessary for tropical species to thrive. Supplemental heat, light, and humidity are provided to sustain a tropical ecosystem among the cool, grey, drizzly days of the Pacific Northwest.

We import about 500 tropical butterflies weekly, from South and Central America, Africa, and Asia. Our butterflies are responsibly raised in sustainable rainforest farms. We are proud to participate in the positive economic, cultural, and environmental impacts butterfly farming makes throughout the world.

Rainy Season Survival Tips

If the Northwest’s dreary fall and winter weather get you down, we have some advice. Stop by and get some therapy.


Follow Our Life Sciences Blog!

To keep up with all that’s happening in our Tropical Butterfly House, and for some great behind-the-scenes stories, be sure to follow our Life Sciences Blog.

Resources For Your Visit

The following resources are available for guests and school groups alike to enhance your learning experience in the Tropical Butterfly House.

Pre-Visit Discussion Ideas & Activities

Butterfly Identification Guide

Butterfly House Plant Identification Guide

Frequently Asked Questions

Butterfly Life Cycle Questions

How long do butterflies live?

Butterflies live a few days to a month or longer. We estimate the average life span to be a couple of weeks.

How long does the entire life cycle take?

It varies according to species and environment. In general, 8-15 days as an egg, a few weeks or more as a caterpillar and a week to 9 months as a pupa. Some butterflies complete a generation in one month! A few species have a two-year life cycle.

Why is this one’s wings damaged? Will it recover?

It may have flown into a window, fallen into a puddle then stuck to something, or chased another butterfly and crashed into something. A careless human touch from may have damaged it. Butterflies lack the physiology to repair damaged tissue; however many butterflies can fly with extensive wing damage.

If their life is so short, how do you get new ones? Do you raise them?

We do not raise our butterflies from eggs, for two reasons:

  1. We do not have permission from the USDA.
  2. We could not sustain enough plant material for them. We purchase our pupae from butterfly farms in tropical countries, where they are sustainably farmed. Supplier names are listed on the boards where the chrysalides are pinned.

Where do your butterflies come from?

The butterflies are imported. We receive weekly shipments of pupae primarily from El Salvador, Costa Rica and the Philippines.

The butterflies are not wild captured, but raised on butterfly farms. Female butterflies are placed in netted areas and supplied with native plants appropriate for their eggs, and the resulting caterpillars are protected and fed until they pupate, and then shipped here. Wild populations are not depleted to obtain these butterflies, and the land where they are farmed is not destroyed.

Perhaps even more important, butterflies are farmed locally by people whose jobs often draw on resources in the rainforests. This provides jobs that promote stewardship of the environment and that bring with them a greater appreciation for the complexity of the butterflies’ natural habitat. Rather than viewing the forest as a commodity to be used as quickly as possible, butterfly farming allows people to find profit in caring for the plants and animals around them. In a world where jobs and the environment are often pitted against each other, butterfly farming supports both at once.

How do you stop them from laying eggs?

Most species of butterfly only lay eggs on certain types of plant. They recognize the plants by distinctive chemicals the plants produce. If the chemicals are not there, butterflies will not be stimulated to lay eggs. To prevent the butterflies from reproducing, we do not grow plants on which they normally lay eggs.

What is a pupa?

A pupa is the stage between larva and adult (in insects with complete metamorphosis) where larval cells and structures gradually reform into adult cells and structures.

What is a chrysalis?

Chrysalis is a special name for the pupa of a butterfly. Chrysalids or chrysalides is the plural. All chrysalides are also pupae. When you look at a chrysalis, what you see is actually its exoskeleton, just as the skin of a caterpillar is its outside. They may resemble bird droppings, parts of plants, or lichens.

What is a cocoon?

A cocoon is an outer casing constructed by larva of silk or dead leaves, which protects the chrysalis. Cocoons are made by moths and other insects.

Butterfly Species Questions

I saw a butterfly at a zoo’s exhibit. Is it a native or a tropical species?

Many butterflies native to the southern tip of the U.S. are also native to Central and South America. No butterfly in our Tropical Butterfly House is a Washington state native, except for the monarch, which is found east of the cascades.

How many butterflies and species are in here?

We don’t know exactly. We try to maintain a population of 800 – 1200. Depending on the time of day and how recently we got a shipment of pupae, there may be more or less activity. We have had over 100 species since we opened. At any given moment, we have fewer.

Why are there ants, fruit flies, slugs, aphids, mealy bugs, etc?

Most nursery plants are treated with insecticides before you buy them, but we purchased untreated plants so the nectar would be safe for butterflies. The plants came with many uninvited critters. We use biological controls and accept that there will be some pest species living in the butterfly house.

Operational Questions

How much do pupae cost?

We pay about $2.50 per pupa, plus shipping fees. We import about 350 – 600 pupae every week.

How and why do you pin them?

We pin the chrysalides to allow air circulation around them, and to place them in the most natural position to emerge. Most chrysalides have a small silk pad attached to the tip of their abdomens. We put the pin through the silk, and into the soft foam of the pinning board. If the silk has come off, we glue the pin to the pupa using a low temperature glue gun.

Why can’t I touch a butterfly? Why is the person in the window touching them?

Any time anyone touches a butterfly, they risk damaging its wings. Even very careful handling can cause damage. Animal care staff are trained to handle butterflies with minimal risk of damage, and we also try to handle them as little as possible.

What do you do when a butterfly is injured or dead?

If a butterfly is only slightly injured, we don’t do anything. If it cannot fly, we humanely destroy it. Dead butterflies are collected, autoclaved, and incinerated or used internally for educational purposes. That is the USDA requirement. We cannot give them to guests, including teachers.

Why is the window dirty?

The windows are dirty due to fluids which newly emerged butterflies release. These fluids can stain, and be a little messy. In case you are worried that butterflies will poop on you, we’ve never had a report of this happening!

Fun fact: caterpillars produce huge quantities of poop. The technical name for caterpillar poop pellets is frass.

Why is it so hot in here?

We grow tropical plants in here, and most of our butterflies are from warm climates. The warm temperature keeps them healthy.

Do you let them sleep at night?

Both the plants and the butterflies need rest. We have the lights on a computerized timer to give the Tropical Butterfly House 8 hours of darkness in every 24 hour period.

Why can’t I take a plant or butterfly?

Plants are slow growing, and damaging or taking parts of them will make the exhibit less enjoyable for others. We are also obligated by our permit to destroy any plant material that we remove from the exhibit.

It is a violation of our USDA permit to remove butterflies. We also want to prevent the passing of parasites to native species or damage an indigenous plant population.

Why shouldn’t I pick a tiny flower and walk around with it?

As long as it is on the plant and producing nectar, that flower is useful to our butterflies. Once picked, it no longer provides nectar. Besides, you will not attract butterflies by showing them the flowers. They can only see wide patches of color, so they probably are not aware that you have a flower in your hand.

Behavioral Questions

Will butterflies bite me?

Absolutely not. Butterflies’ mouthparts do not allow them to bite, chew, pierce or even nibble. They are tube-shaped, like straws, to sip. That is why we have to let the fruit in the feeders get so icky. Until it is over-ripe enough to exude juices, the butterflies cannot eat it. The butterfly only eats solid food in its larval stage.

Why did it land on me? Why won’t it land on me?

We haven’t found a formula for why butterflies land on certain people. We’ve found that they are attracted to bright colors, especially red and yellow. If a butterfly doesn’t land on you, don’t be disappointed! Please don’t try to make it crawl onto you.

Why is this butterfly on the ground?

Butterflies don’t always want to be flying. They need to rest too! The butterflies are not aware that the walkways are bad places to land. Please be careful to watch your step so you don’t disturb the resting butterflies. You may also notice that they often land on the ground near fans. Butterflies enjoy the airflow and will often position themselves so that they are oriented near it.

What are those butterflies doing?

You may see 2 butterflies attached at the abdomen. These butterflies are mating. Once a mate is chosen, the male grasps onto the female’s abdomen with claspers. He transfers sperm into her abdomen, where it is stored in a special pouch. When the female lays her eggs they pass through this pouch and are then fertilized.

What happens when they emerge?

First the legs emerge. They reach out, find something to hold onto and pull the rest of the body out. The wings are small and soft, but soon expand as the butterfly pumps fluid into them. When they are fully expanded, the wings can dry. The butterfly excretes excess fluid, and is ready to be released. We do two releases each day. Even if butterflies are ready to go, they wait. Opening and closing the emerging window dries out the chamber, and can cause damage to the pupae.

Background Questions & Classifications

What is an arthropod?

Arthropod refers to a phylum of invertebrates characterized by having an exoskeleton, segmented body and jointed appendages.

What is an insect?

Insecta is a class of arthropods. To be an insect you must have three body segments (head, thorax, abdomen) three pairs of legs, antennae, compound eyes, & usually one or two pairs of wings.

What is a Lepidoptera?

Lepidoptera is the order of invertebrates that contains butterflies, moths, and skippers. The name means scale wing. Both butterflies and moths wings are covered in small overlapping scales. This is why we must be so careful to not touch their delicate wings.

Currently there is no scientific consensus as to the exact date of when moths/butterflies appear in the fossil record. Here are two of the most popular opinions:

The first primitive moths appear in the fossil record about 140 million years ago, during the Age of Dinosaurs. The oldest known fossil butterflies date to about 40 million years ago, from the Age of Mammals. OR: The first primitive moths are found in Cretaceous amber which dates from the Age of Dinosaurs, over 70 million years ago. The oldest known fossil butterflies are from Green River Shale in Colorado, which dates from the Age of Mammals, about 48 million years ago. [Different sources differ on the ages.]

The closest relatives of Lepidoptera are the caddisflies (Trichoptera). The caddisfly larva resembles a caterpillar and spins a cocoon out of silk. Like Lepidoptera, caddisflies have wings with a large surface area. Some caddisflies link their front and hind wings in flight as moths do.