The cat is chasing two mice. They are afraid of the cat.
mouse:名词复数: mice;
chase:用作及物动词 (vt.),可以直接加宾语,也可以加after,可以省略不要。
He chased (after) the thief but couldn't catch him.他追赶小偷却未捉住。
The cat is chasing after two mouses.They’re afraid of the cat.