Monarch Migration!

The monarchs are here! After a record wildflower bloom this year, we’ve been expecting record numbers of monarch butterflies, and we just spotted the first ones enjoying the Butterfly Garden in our Science and Art Park.


These beauties travel through Central Texas two times a year, heading to Mexico for the winter and returning to Canada for the summer. On the Texas A&M website, Craig Wilson, USDA Future Scientists Program Director, estimates that we could see 300 million monarchs pass through the state, and that’s encouraging after several years of declining numbers.
“Butterflies are not only fun to watch, but they serve a critical purpose as well,” said Zac
Zamora, Science Mill Creative Director. “Butterflies and other pollinators, including bees,
moths, birds, and bats pollinate over 75% of the world’s flowering plants.”

Attracting monarchs and other pollinators requires the right kinds of plants. When planning the Science Mill’s Butterfly Garden, we learned that not all milkweed is good for monarchs. It’s important to get native plants that are in sync with local seasons. This goes for other varieties of plants in your garden, too. Encouraging healthy pollination locally can have a global impact. To attract pollinators, our Science Mill garden includes these plant varieties, all available at local nurseries:


You can be part of this year’s historical monarch migration by planting your own butterfly
garden and reporting sightings on the Journey North website. And check out our Butterfly Garden at the Science Mill!

We've Gone Batty!

Texas is home to more species of bats than anywhere else in the world. In fact, the Science Mill sits between two record-breaking bat colonies. The largest bat colony in the world is located near San Antonio, at the Bracken Cave Preserve, and the largest urban bat colony is in downtown Austin, under the Congress Avenue Bridge.

This month, in preparation for our Bat Bazaar event on October 19, we’re gobbling up bat facts like our bat friends gobble up insects. One of our favorite facts is how bats navigate through the dark Central Texas nights, using echolocation to identify objects and food sources.


What is echolocation, exactly?

Echolocation is how certain animals use sound to see. They make sounds that echo off other objects, and depending on how the sounds bounce and return to their ears - and the direction the sound comes from - the animal can determine the location of the objects around them. Bats, dolphins, whales, shrews, and some birds all use echolocation to find food and navigate their environments.

Blind as a bat?

Bat blindness is a common myth, but Arizona State University biologists explain that bats can see.

“Using echolocation, bats can detect objects as thin as a human hair in complete darkness. Echolocation allows bats to find insects the size of mosquitoes, which many bats like to eat. Bats aren't blind, but they can use echolocation to find their way around very quickly in total darkness.”


Can people echolocate?

Some people can! There are instances of visually impaired people learning to use echolocation.

Humans have also developed a form of echolocation that helps engineers and scientists see under water. Sonar, originally an acronym for Sound Navigation and Ranging, helps scientists map the ocean floor. Sonar is also used to find objects in the ocean, like shipwrecks.


What is it like to navigate by sound?

Come to the bat bazaar to experience our Sonar Simulator Challenge, and see if you can navigate like an echolocating bat!

Join us on Saturday, October 19 from 11am-2:30pm for hands-on Bat Bazaar activities. Southern Wildlife Rehab will be on site with three different species of live bats and live presentations at 11:30am and 1:30pm. We think you’re guano love this event! Plus…

Visitors who dress up in their Halloween costumes will receive FREE Excavation Kits from our Science Store!*

Live presentations and all bat activities are included in museum admission.

*While supplies last.

Tortoise Hatchlings

At the Science Mill, our focus is bringing STEM - Science, Technology, Engineering, and Math - to life. One of our favorite ways to do this is through living exhibits, like our odd little axolotls and our aquaponics greenhouse. We are also home to some pretty adorable tortoises!

The African Spurred Tortoise exhibit is a great place to focus on biology disciplines, including zoology and life sciences. Visitors get an up-close look at these gentle giants in their outdoor tortoise habitat. Weekend visitors to the Science Mill are invited to join us for our Tortoise Talks to learn more about what they eat and how they behave.

“The tortoises were my favorite,” said Pete S., 10, a recent Science Mill visitor. “They are giant, and also so cute, plus I liked watching them to see how they move and eat.”
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On March 25, 2019, one of the Science Mill’s African Spurred Tortoises, Tortilla, laid a clutch of 24 eggs, which Science Mill biologists dug up and placed in an incubator to protect them from predators. Over the following months, the eggs were observed for signs of development. Not all eggs were viable, but we’re thrilled to report that after 106 days in the incubator, six eggs hatched between July 9 and 12. Weighing in between 29-36 grams each, these tiny tortoises will grow quickly, eventually weighing over 100 pounds when they are adults (the males could even break 200 pounds!).

These fascinating animals are the only animals that have both a shell and a backbone, but that’s just one of many cool tortoise facts. Did you know…

  • They are the largest mainland tortoise species, and only island tortoises from Aldabra and Galápagos are bigger.

  • What makes it a tortoise, and not a turtle? According the San Diego Zoo, “It depends on who you ask or where you are in the world, but most people recognize tortoises as terrestrial or land-loving with stubby feet (better for digging than swimming) and a heavy, dome-shaped carapace. Aquatic and semi-aquatic turtles are known as just that, turtles. Turtles tend to have more webbed feet (but not always) and their shells are more flat and streamlined.”

  • They are native to the the scrub and grassland found south of the Saharan desert.

  • Tortoise shells are made of keratin, like our fingernails. They can feel pressure and pain through them.

  • African Spurred Tortoises can live over 100 years if provided with proper dietary needs and husbandry (the science of breeding and caring for animals).

  • Speaking of diet, they are herbivores. It is important to offer them a high fiber diet, such as grasses and leaves, in captivity. Too many fruits and veggies can upset their digestive tract.

  • At the Science Mill, we feed our tortoises a variety of lettuces, spinach, bramble, sorrel, and leaves from fruiting plants such as papaya, cucumber, and pumpkin.

  • About 2 months after mating females will dig a nest and will normally lay about 15-30 eggs. Eggs will typically incubate for 100-120 days before hatching.

  • Baby tortoises are about the size of ping pong balls when they hatch out of their eggs by using a specialized egg tooth that drops off shortly after hatching. What a cool tool!

The Science Mill got to see these egg teeth in action when we welcomed our baby African Spurred Tortoises to our family this summer.

Babies as special as these deserve names just as unique, and we need your help choosing the perfect names. Please vote for your favorite name today!

Was it a Sharknado? Local STEM Museum Swimming in Sharks!

July 2019, Johnson City Texas - The Science Mill in Johnson City, TX has discovered that their property contains a fully intact prehistoric Megalodon shark jaw, hundreds of shark teeth buried in the sand in one of their outdoor exhibits, and... a flying shark. This phenomenon occurs once a year at the Texas Hill Country science museum, which is many miles from the nearest ocean.

“We think it’s going to take community involvement to uncover the shark teeth, and learn everything we can about them,” said Science Mill Director of Operations, Portia Marchman. “We hope visitors from all over Central and South Texas will come help us unravel this phenomenon.”

As part of their effort to figure out the mystery, The Science Mill has acquired a film, Great White Shark 3D, to help them study sharks and understand their behavior. They are inviting the public to view the film, as well.

“Please help us by coming to the Science Mill, watching the 3D movie, digging for shark teeth, taking photographs of the giant Megalodon jaw, and letting us know what you’ve learned,” said Marchman.

The Science Mill is hosting Shark Week, July 31-August 4, during regular business hours. Visitors are invited to get hands-on with shark-related activities, like:


Special showings of Great White Shark 3D Movie*

Misrepresented, maligned and misunderstood, the Great White Shark is an iconic predator. Shot on location in South Africa, New Zealand, Mexico and California, the film looks to find the truth behind the mythical creature forever stigmatized by its portrayal in the world’s first blockbuster movie, JAWS.

*3D movie is included in museum general admission. See front desk for movie showtimes. Note: EarthFlight 3D will play between scheduled showings of Great White Shark 3D; check at the front desk for schedule.

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Dig for Real Shark Teeth!

Grab a shovel and take home some real shark teeth hidden in the Fossil Dig in our Science + Art Park. While you’re at it, discover dinosaur bones and other prehistoric fossils hidden beneath the sand.


Take a Photo with a Prehistoric Megalodon Shark Jaw!

Step inside our life-sized Megalodon shark jaw, fabricated on site at the Science Mill, for an out-of-this-world photo op coveted by any true shark lover!


Shark Week Trivia

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Megalodon Shark Teeth 3D Printing 

Watch a giant megalodon shark tooth get 3D printed right before your eyes. Stop by the gift shop and take home one of your own!



Become a Science Mill Member in July, and your Shark Week adventures will be free! The Science Mill is also giving away one shark or bug book per membership, while supplies last. Get more information and join now!