there is a coworker sitting next to me that he is making noise with his pen the whole day long . it is disturbing me from my work . that 's got to be annoying ! have you tried telling him to stop ? i already told him but he said he ca n't concentrate without having something in his hands . maybe he should take up knitting -- or something else that would be a bit more quiet .
The coworker's persistent pen-clicking noise is the cause of the annoyance.