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。

youdao

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。

youdao

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。

youdao

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