TOEFL---IBT閱讀材料：Ants Protect Acacia Trees from Elephants

曾經有人認為老鼠是大象的天敵，而事實上，這些陸上最龐大的哺乳動物們最厭惡的動物竟然是小小的螞蟻!正因為有螞蟻的存在，大象會盡量避開洋槐樹。


We all know that elephants aren't really scared of mice. But a new study shows that they're really not crazy about something even smaller: ants. In fact, elephants dislike ants so much that they avoid acacia trees that harbor the tiny, six-legged nectar-suckers.

On the savanna, acacia trees growing in regions that get a lot of elephant traffic tend to get eaten. But researchers noticed that one species of acacia was not much bothered by elephants. And that the untouched acacia was a favorite ant habitat.

So the scientists stripped the ant-covered acacia of their bodyguard bugs, and sure enough, the elephants chowed down. In addition, when the insects were placed on previously ant-free acacias, the elephants took a pass.

But how can teeny, tiny ants repel a big old elephant, which is, after all, about a billion times more massive? The answer is in the trunk. Or rather, not in the trunk. Because, as you can probably relate, elephants really hate to have ants up their noses.

The research is published in the journal Current Biology. [Jacob Goheen and Todd Palmer, http://bit.ly/8ZSmpa which includes video] And it suggests that adding ants could help preserve wooded areas on the savanna. Because ants will ruin any picnic, even for pachyderms.