A father and daughter got into an argument about their calico cat, and whether her markings were splotches or patches. The daughter said her Dad was being trivial, and then uttered this malaphor. It is a congruent conflation of “splitting hairs” and “nitpicking” or “picking (something) apart”, all meaning to make small or overfine distinctions. Hope no one has trichotillomania. A shout out to a familiar name on this website, John Kooser (aka “the Dad”) for sending this one in.