Why does Cherubino hide when Count Almaviva enters Susanna’s room?

In Act I of Mozart’s The Marriage of Figaro, Cherubino hides behind a chair in Susanna’s room because he is a teenager who has been caught by Count Almaviva with young Barbarina. Fearing the Count’s anger and his threat to make him leave the castle, the page seeks to avoid detection when the Count arrives to pursue a tryst with Susanna.1

The situation becomes more complicated when Don Basilio also arrives, forcing the Count to seek his own hiding place. The Count moves toward the chair concealing Cherubino, which forces the boy to jump into the seat, where Susanna quickly covers him with a cloth to keep him hidden.1