Lemur of mouse lemurs, the gray mouse lemur ("M. murinus"), golden-brown mouse lemur ("M. ravelobensis"), and Goodman's mouse lemur ("M. lehilahytsara") were considered the same species until recently, when genetic tests identified them as cryptic species. The lemur dentition is heterodont (having multiple tooth morphologies) and derives from an ancestral primate permanent dentition of . Indriids, sportive lemurs, the aye-aye, and the extinct sloth lemurs, monkey lemurs, and koala lemurs have reduced dentitions, having lost incisors, canines, or premolars. The ancestral deciduous dentition is , but young indriids, aye-ayes, koala lemurs, sloth lemurs, and probably monkey lemurs have fewer deciduous teeth.
U Should've Known Better backbeat, the song's instrumentation consists of screeching guitars and an understated harp pattern. Lyrically, Monica, as the protagonist, delivers a message of loyalty to her imprisoned love interest and sings about staying down for him despite his doubts. The song was generally well received by contemporary music critics who highlighted the heartfelt emotion and sadness. Released as the fourth and final single from "After the Storm" in May 2004, the single marked Monica's first balladic release in over five years. On the charts, "U Should've Known Better" peaked at number 19 on the US "Billboard" Hot 100 and number 6