A bee steps onto this Venus fl ytrap’s leaves. The trap has not yet sprung.


Plants That Trap Bugs A Venus flytrap eats bugs. To catch bugs, it


makes a trap with its leaves. Its spiked leaves come together to form a “V.” When a bee walks across its leaves, they


snap shut. T ey spring together in less than one-tenth of a second, trapping the bee. Once the leaves are closed, the plant eats the bee. Scientists wondered what made the trap


close. T ey wondered how a bug could trigger the trap, but rain couldn’t. Over time, scientists tried many experiments. T ey shared their results with one another. T anks to these experiments, we now know


how the trap works. Fine hairs cover the plant’s leaves. T ese hairs act as triggers. When an insect walks by several hairs, the leaves close. If the plant feels the insect moving inside, it keeps the leaves closed. Rain doesn’t close the trap because each drop only hits the hairs once.


22 NATIONAL GEOGRAPHIC EXPLORER


A Sense of Smell You may now think that plants are pretty


complicated. Many scientists have done lots of experiments to figure this out. Yet sometimes scientists observe things that


they can’t easily explain. Here’s an example. My grandmother didn’t study plants. Yet she knew how to get a hard avocado to soſt en. She put it in a brown paper bag with a ripe banana. It works, but scientists asked: Why does it work? We had a tough time figuring it out. It turns out that the banana gives off a


chemical. T e avocado can smell this chemical. T is smell causes the avocado to ripen quickly.


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