старого воробья на мякине не обманёшь

Set phrase: a fox is not taken twice in the same snare, an old bird is not caught with chaff (an experienced, wise, clever person is not to be enticed, fooled so easily), an old bird is not to be caught with chaff, an old fox is not easily snared, no playing with a straw before an old cat, old birds are not caught with chaff, old birds are not to be caught with chaff