In "Sinners in the Hands of an Angry God," to what two creatures does Edwards compare sinners?

In his sermon, Edwards first compares sinners to spiders or other disgusting insects:

. . . [God] holds you over the pit of Hell, much as one holds a spider, or some loathsome insect . . . .

In the same paragraph, he compares sinners to poisonous snakes:

. . . you are ten thousand times more abominable in his eyes than the most hateful venomous serpent is in ours . . . .