ZooMissouri, US

Monsanto Insectarium

Discover the fascinating world of invertebrates at the Monsanto Insectarium (now Bayer Insectarium).

About

Discover the fascinating world of invertebrates at the Monsanto Insectarium (now Bayer Insectarium). This unique 9,000-square-foot facility at the St. Louis Zoo offers an eye-opening journey into the lives of insects, spiders, and other amazing arthropods, blending education with active research. It stands as one of the few dedicated insectariums in North America, providing an intimate look at creatures often overlooked but vital to our ecosystem.

Within its more than 20 major exhibit areas, visitors can observe over 100 species of live insects, often catching a glimpse of invertebrate keepers at work or even interacting with entomologists through a dedicated window. The Insectarium's diverse collection showcases everything from vibrant beetles and masterfully camouflaged stick insects to industrious leafcutter ants and impressive tarantulas. While the beloved Mary Ann Lee Butterfly Wing, a geodesic flight dome once home to a kaleidoscope of rainforest butterflies like Paper Kites and Malachites, is currently closed due to storm damage, the rest of the Insectarium remains a vibrant hub of activity.

A visit to the Monsanto Insectarium is an unforgettable adventure that transforms perceptions of the insect world. It's a place where you can witness the intricate behaviors of tiny creatures, learn about their crucial roles, and appreciate the often-hidden beauty of these mini-beasts. The exhibits are designed to engage all ages, making it a memorable stop for anyone curious about the smaller, yet incredibly significant, inhabitants of our planet. Turn your visit into a safari! Use the Snappit app to scan and log wildlife sightings here.

The Monsanto Insectarium, originally named after its sponsor, opened its doors to the public in 2000 as a significant addition to the St. Louis Zoo. Designed by David Mason & Associates and constructed at a cost of $4 million, this 9,000-square-foot facility was established with a dual purpose: to serve as a hub for insect research and to educate the public about the importance of invertebrates. The facility has since been renamed the Bayer Insectarium, maintaining its mission as a leading center for entomological study and public engagement.

What to do here

Engage with the interactive exhibits, search for camouflaged creatures, and take time to observe the intricate behaviors of the resident invertebrates.

Seasonal info

While the Butterfly Wing previously offered a warm escape during colder months, it is currently closed indefinitely. The rest of the Insectarium remains open year-round.

Accessibility

The Monsanto Insectarium is located within the highly accessible St. Louis Zoo. The facility itself, along with most restrooms, is wheelchair accessible. The Zoo provides maps indicating ramps and accessible pathways. Manual wheelchairs and electric scooters are available for rent at the Zoo's north and south entrances.

Don't miss

Live Insect Displays

Observe a wide variety of insects, arachnids, and other invertebrates in naturalistic habitats.

Keeper Interactions

Watch zookeepers tending to the animals and potentially interact with entomologists at their research stations.

Leafcutter Ant Colony

Witness the incredible industriousness of leafcutter ants as they transport leaf fragments to their fungus farms.

Stick Insect Displays

Marvel at the masterful camouflage and unique forms of various stick insect species.

Wildlife you might spot

Each card links to a full Explore page with photos, traits, and fun facts.

Bee

Carpenter Bee

American Robin

Duck

Monarch Butterfly

Canada Goose

Northern Cardinal

Eastern Gray Squirrel

Snap map for this place

Start with the big picture, then zoom in to explore individual wildlife observations around this place.

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Good to know before you go

Arrive Early

Visit right at opening, especially on weekdays, to experience fewer crowds and more intimate viewing opportunities.

Look Closely

Many insects are masters of camouflage; take your time to carefully scan the exhibits to spot hidden creatures.

Check for Keeper Talks

Inquire about any scheduled keeper talks or feeding demonstrations for a chance to learn directly from the experts.

Use the Zoo Map

The St. Louis Zoo is large; grab a map at the entrance to plan your route and easily locate the Insectarium within Discovery Corner.

Stay Hydrated

Even though the Insectarium is indoors, exploring the wider zoo can be extensive. Bring a water bottle or plan for refreshment stops.

Consider Behind-the-Scenes Tours

The zoo sometimes offers "Planet Protectors" tours for a deeper dive into the insect world and keeper work (check the zoo's website for availability and booking).

Frequently asked questions

: No, admission to the Monsanto Insectarium, like the rest of the St. Louis Zoo, is completely free.
: The Mary Ann Lee Butterfly Wing sustained significant storm damage in May 2025 and is currently closed indefinitely while repairs and safety measures are being addressed. The rest of the Insectarium remains open for visitors.
: The St. Louis Zoo operates on a cashless payment system. However, cash-to-card kiosks are available on-site to convert cash into a prepaid Mastercard for use anywhere Mastercard is accepted.