The Boys and the Frogs by Marmaduke Park

Some boys, beside a pond or lake,
Were playing once at duck and drake?
When, doubtless to their heart's content,
Volleys of stones were quickly sent.
But there were some (there will be such)
Who did not seem amused so much;
These were the frogs, to whom the game,
In point of sport was not the same.
For scarce a stone arrived, 'tis said,
But gave some frog a broken head;
And scores in less than half an hour,
Perished beneath the dreadful shower.
At last, said one, "You silly folks, I say,
Do fling your stones another way;
Though sport to you, to throw them thus,
Remember, pray, 'tis death to us!"

Who are the characters in this poem?