Why didn't Stanley tell the other boys about the poison fingernails polish holes?

Stanley didn't tell the other boys about the poison fingernail polish holes because he likely wanted to protect them from unnecessary panic and danger. Additionally, he might have felt that sharing such information could lead to chaos or conflict among the group, which was already facing numerous challenges at Camp Green Lake. Keeping the information to himself allowed Stanley to think strategically about how to handle the situation without adding to the existing tension.