but the snakes are literally in the dark - 而蛇则完全处于黑暗之中

228. A bottleneck funnels these exiting bats into dense concentrations
     当大群蝙蝠密集地通过瓶颈出口时
229. attracting the attention of others.
     很容易引起其它动物的注意
230. The bats can detect the snakes using echolocation,
     蝙蝠能利用回声定位觉察到蛇
231. but the snakes are literally in the dark -
     而蛇则完全处于黑暗之中
232. they can see nothing.
     它们看不见任何东西
233. The strikes seem to be largely hit-and-miss,
     这种攻击更像是在碰运气
234. but the snakes have a secret weapon.
     不过蛇也有自己的秘密武器

来自《行星地球 第一季 第四集 Planet Earth S01E04 洞穴》第 231 行