Bridge Full of Bats

When we think of cities, we picture crowds of people, pets, pigeons… but bats?? That’s the fact in Austin, Texas, where tons of bats hang out in the Congress Avenue Bridge. 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. All those bats eat 10,000 to 20,000 pounds of bugs every night.

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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