The rats used in the tunnel scene were specially-trained and colored with a dark, charcoal-like substance to give them the appearance of wild, dirty tunnel rats.

地铁隧道场景中动用的老鼠都是经过特殊训练的，它们全身涂满了类似于煤炭的深色物质，以让它们看起来像是野生肮脏、生活在隧道里的老鼠。

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The rats could choose to switch boxes through a tunnel that connected both boxes.

老鼠们会通过盒子的通道跑到另一个盒子里。

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The rats' teeth chattered, and the creatures were unwilling to venture forth into the open arm of their maze, preferring to stay in a tunnel area.

大鼠的牙齿格格作响，不愿前往臂杆开启的迷宫，宁愿待在隧道区域。

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After extremely rare desert rainstorms, the lazy rats will tunnel furiously toward other colonies, looking for female mole rats willing to provide them with infrequent workers of their own.

NPR: Mole-Rats, Ants Making Science Headlines