She felt that he was beginning to smell a rat.
It was only a matter of time before his family smelled a rat.
We had to have two of the family on the board so they wouldn't smell a rat.
"That man would have smelled a rat and reported him to the police."
He'll smell a rat and wonder how much we know about his island.
Not that they didn't smell a rat now and again.
But I do smell a rat in the way we think and talk about war.
Do you mean to tell me they smell a rat?
If these are indeed true I certainly smell a rat.
The risk was too great that I'd smell a rat.
Idiome