Types of Participle Clauses:
The perfect participle, active (having -ed) is used to show that the event of the participle clause happened first. The clauses can be in either order: Having eaten all the food it could find in the camp, the bear wandered away.
The perfect participle, passive (having been -ed) is used when the action of the participle clause happens before the action of the main clause. The participle clause usually comes first: Having been attacked during his previous visit, he was very careful about where he went.
The past participle (-ed) has a passive meaning. The participle clause usually comes first. It can express1 cause: Ignored by the other children, the boy played by himself. (= Because he was ignored ...) 2 description: Surrounded on three sides by mountains, the village rarely enjoys much sunshine. 3 condition: Kept in a cool place, yoghurt will remain fresh for a long time. (= If yoghurt is kept in a cool place ...)