Some synonyms for the word "misbehaved" is naughty and mischievous.
in addition to, plus, also, as well, furthermore, including, moreover
lives, breathes, subsists, transpires, happens, amounts to, equals, comprises, signifies, means exists
rivulets is the plural form of the word "rivulet," which means "small stream." So, stream would work as a synonym.
there is no such syno. for the word their..