I had a RIR chick that did this. She went around to all the other chicks in the brooder and would peck at their eyes. It stopped after a day or two, and everyone was OK.
It may help to add some distractions to the brooder to give them something else to focus on, for example: 1) a dish of mashed hard-boiled eggs to give them something new to peck at, 2) a small dish of colored marbles to give them something else that's shiny to peck at, and/or 3) a couple of 3" diameter branches to give them something to perch on, sleep next to, navigate around, and provide semi-isolation areas.
It may help to add some distractions to the brooder to give them something else to focus on, for example: 1) a dish of mashed hard-boiled eggs to give them something new to peck at, 2) a small dish of colored marbles to give them something else that's shiny to peck at, and/or 3) a couple of 3" diameter branches to give them something to perch on, sleep next to, navigate around, and provide semi-isolation areas.