smell a rat

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.