"Picks nits" is a phrase commonly used to describe someone who is excessively critical or finds minute flaws in something. However, there are many other synonyms that can be used to convey the same meaning. Some of these include: nitpicks, quibbles, fusses over, hyper-analyzes, finds fault, nitpicks, scrutinizes, and hairsplitting. Each of these phrases highlights the same behavior of being overly critical and nitpicking, but can be used in different contexts for varied impact. When writing or speaking, it can be useful to have a range of synonyms at one's disposal to convey the desired meaning and tone.