Bridge Full of Bats

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

Bridge Full of Bats

June 30, 2014

The bat is a strange, spooky animal. It looks like a mouse with spiky wings, and makes squeaky sounds to find the insects it’s hunting down to eat. These creepy fliers get creepier when they form big groups, and the biggest, most alarming crowd of these might be the Congress Avenue Bridge bats in Austin, Texas. Thanks to cavelike holes in the underside of the bridge, over a million bats live in there, and every summer evening all 1 1/2 million of them fly out in a giant swarm to hunt insects all night. At first, the people who live in Austin were freaked out and wanted the bat colony destroyed, until they learned that the bats together eat 10,000 to 20,000 pounds of insects every night, including mosquitos and bugs that eat farm crops. Once everyone did the math, they realized that while the bats might not be cute, they’re very helpful.

Wee ones: Bats have 2 wings, but many bugs they chase have 4 wings each. Who has more wings, the bat or the bug?

Little kids: Every spring the bats migrate to Texas from Mexico, and leave in the fall. If they live in Austin from beginning of June to end of October, how many full months do they spend in Austin?  Bonus: 100,000 people watch the Austin bats every year. How many will see them in 5 years?

Big kids: Each year a mama bat can give birth to 1 baby, which weighs 1/3 as much as she does. Imagine that for people: if your mom weighed 120 pounds at your birth (not counting your weight), how much would you have weighed as a baby?  Bonus: If the bats stay in town for 5 months and together eat 10,000 pounds of bugs every night, how many pounds do they eat during their whole stay? (Assume 30 days per month. Hint: Start off by seeing what it would be for 1,000 bugs a night…)




Wee ones: The bug.

Little kids: 5 months.  Bonus: 500,000.

Big kids: 40 pounds.  Bonus: 1,500,000 pounds. Yuck!

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About the Author

Laura Overdeck

Laura Overdeck

Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.

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