have straws in (one's) hair
obsolete To be insane or mentally deranged; to be or have been a patient of a mental institution. The more sensationalist newspapers have taken to saying he has straws in his hair, but I think that he knew full well the scope and impact of his crime.
straws in your hair
a state of insanity. In former times, the floors of mental institutions were covered with straw, and so having straw in the hair came to be regarded as a characteristic of a deranged person.