- And while they're up here
它们高悬在洞穴上方时 - the bats produce something very important.
会产生一种非常重要的东西 - This hundred metre high mound is made entirely of bat droppings -
这堆100多米高的东西 全都是蝙蝠的排泄物 - guano.
粪便 - Its surface is covered by a thick carpet of cockroaches,
地面上爬满了密密麻麻的蟑螂 - hundreds of thousands of them.
它们的数量无以为计 - Caves are one of the few habitats on Earth not directly powered by sunlight.
洞穴是地球上少数几种 不直接依赖阳光的生态环境之一