They said they'd help but they have rat on their friend.
I saw a rat on the table and wantonly eating the cake.
We should not rat on our promises.
We should not rat on our debts.
Don't rat on me! Never, upon my soul.
A rubber rat on top of an overflowing garbage can is a nice touch.
I noted that Rogan had a tattoo of a rat on his neck, a rat that had just been knifed and was crying.