厨房里发现了一只老鼠，我们得赶紧买些捕鼠器。

We found a ___rat in the kitchen and need to buy some traps immediately.

他背叛了团队，现在大家都叫他叛徒（老鼠）。

Everyone calls him a ___rat after he betrayed the team.

他不想告密，但最后还是把同伙的秘密告诉了警察。

He didn't want to ___rat on his partners, but ended up telling their secrets to the police.