1) Be suspicious 2) Become suspicious 3) Get suspicious 4) Harbor suspicion 5) Sense something wrong 6) Suspect chicanery 7) Suspect fishiness 8) Suspect something 9) Suspect something is fishy Found on https://www.crosswordclues.com/clue/smell-a-rat
1) Be suspicious 2) Become suspicious 3) Get suspicious 4) Harbor suspicion 5) Sense something wrong 6) Suspect chicanery 7) Suspect fishiness 8) Suspect something 9) Suspect something is fishy