【英语时差8,16】螳螂的眼睛（下）

There are many dung beetles² competing for a limited amount of food at a dung pile, so when an individual is finished rolling a ball of dung it is in its best interest to make a quick escape. The fastest way to travel is in a straight path. Scientists noticed that when the moon was visible, these dung beetles did just that; they traveled in straight paths. But when it was a cloudy night, the beetles’ paths became shaky and erratic³. To be sure the beetles were indeed using the moon’s polarization and not the moon itself, the researchers used a filter that changed the pattern of the polarized moonlight by 90 degrees. The beetles responded by changing their course by 90 degrees. Scientists suspect that the dung beetle¹ isn’t the only animal to navigate⁴ by the moon’s polarization and that more such creatures will soon be discovered.

1 beetle   

n.甲虫，近视眼的人

参考例句：

• A firefly is a type of beetle.萤火虫是一种甲虫。
• He saw a shiny green beetle on a leaf.我看见树叶上有一只闪闪发光的绿色甲虫。

2 beetles   

n.甲虫( beetle的名词复数 )

参考例句：

• Beetles bury pellets of dung and lay their eggs within them. 甲壳虫把粪粒埋起来，然后在里面产卵。 来自《简明英汉词典》
• This kind of beetles have hard shell. 这类甲虫有坚硬的外壳。 来自《现代汉英综合大词典》

3 erratic   

adj.古怪的，反复无常的，不稳定的

参考例句：

• The old man had always been cranky and erratic.那老头儿性情古怪,反复无常。
• The erratic fluctuation of market prices is in consequence of unstable economy.经济波动致使市场物价忽起忽落。

4 navigate   

v.航行，飞行；导航，领航

参考例句：

• He was the first man to navigate the Atlantic by air.他是第一个飞越大西洋的人。
• Such boats can navigate on the Nile.这种船可以在尼罗河上航行。