英语听力：自然百科 大迁徙之繁衍生息 Need to Breed—10（在线收听）

 The nursery lies at the heart of a twitching, thriving structure, built almost entirely of the aunts of themselves. Long legs stuck together with tussle cores. They are the scaffolding, bricks, and mortar of the nests. But they’ve been in one place for 3 weeks, ravaging the forest floor from miles in all directions. It's time to migrate。