Identify the participial phrase in each sentence. 9. the boys, having finished their dinner, rushed to the baseball field. 10. told of a possible flu epidemic, the employees signed up to be inoculated. 11. the girls were frightened at the strange noises coming from the old house. 12. i see a thread hanging from your shirt.

The correct options are as follows, the participial phrases are written in capital letters:
9. The boys, HAVING FINISHED THEIR DINNER, rushed to the base ball field.
10. TOLD OF A POSSIBLE FLU EPIDEMIC, the employees signed up to be inoculated.
11. The girls were frightened at the strange noises COMING FROM THE OLD HOUSE.
12. I see a thread HANGING FROM YOUR SHIRT.

A participle is a verbal that is used as an adjective and it always end in 'ing or 'ed'. Participles modify pronouns and nouns. There are two types of participles, present and past participles. A participial phrase is made up of a present participle or a past participle, modifiers, objects and complements. In a sentence, the participial phrase can appear before the main clause, after the main clause or in middle sentence position. 

Lady, you are the cruelist she alive, if you will lead these graces to the grave, and leave the world no copy.