Sitter's Bane is a term used to describe the difficult job of babysitting. It is made up of two words, BRAT and IMP, which are both four and three letters respectively. BRAT stands for a mischievous child who often causes trouble, while IMP stands for a mischievous person or creature. Together, these two words describe the challenge of babysitting, as it can be difficult to manage a mischievous child or person.