A stilted story

　　踩高跷的故事
　　Jun 29th 2006

　　From The Economist print edition

　　IF THERE were a Royal Society for the Prevention of Cruelty to Ants, Matthias Wittlinger of the University of Ulm, in Germany, would probably be top www.med126.com of its hate list. The reason is that Dr Wittlinger and his c________① have, as they report in this week's Science, been chopping the feet off ants. And not only that. They have been making other ants walk around on stilts.

　　假如有一个皇家防止残害蚂蚁协会的话，德国乌尔姆大学的马提亚 威特林格可能会首当其冲地成为其憎恨对象。这是因为威特林格博士和他的同事们在本周《科学》杂志上报道说他们砍去了一些蚂蚁的脚。这还不算，他们还让别的蚂蚁踩着高跷走路。

　　Saharan desert ants of the genus Cataglyphis have to travel long distances to discover food in their i________②, sandy environment. How they find their way home once they have done so is a mystery. Ants in more temperate climates often lay down chemical trails, but Cataglyphis, apparently, does not. Like honeybees and ancient mariners, they can n_______③ by the sun, so they know the general direction in which to travel. But, also like ancient mariners (who knew their latitude, but not their longitude), such solar reckoning cannot tell them when to stop.

　　撒哈拉沙漠的箭蚁不得不在贫瘠的沙质环境中长途跋涉寻找食物。它们找完食物后如何返回蚁巢却一直是个谜。温和气候环境下的蚂蚁往往会在路途中留下化学记号，可箭蚁显然不会。它们跟蜜蜂和古代海员一样，可以通过日照导航医学全在,线www.med126.com，从而知道出行的大致方向。但是也跟古代海员一样(他们只会辨认纬度不会辨认经度)，这种根据太阳测算位置的方法无法告知它们该在何时结束行程。