Spanish "Hay gato encerrado": cats, rats and fish?
What do cats, rats and fish have in common? If you take into account the Spanish idiom "hay gato encerrado" (literally "there's a cat locked up") then plenty. The translation into English can be: "there's something fishy going on", "it sounds fishy" or "I smell a rat". Here's a short example:
Pepe: El gobierno dice que va a bajar los impuestos un 20% el año que viene.
María: No sé, creo que aquí hay gato encerrado.
Pepe: The government says that they're going to lower taxes by 20% next year.
María: I don't know - it sounds fishy to me.