Our rabbis said: Even those things which you may regard as completely superfluous to the creation of the world, such as fleas, gnats, and flies, even they too are included in the creation of the world, and the Holy One, blessed be He, carries out His purpose through everything, even through a snake, a scorpion, a gnat, or a frog.
R. Eleazar was sitting to ease himself in the privy, when a Roman came and drove him away and sat down. 'This has a purpose,' remarked he [R. Eleazar]. Immediately a snake emerged and struck and killed him. At that he applied to himself the verse, Therefore will I give a man for thee (Is. 43:4)
When the wicked Titus entered the Holy of Holies, he dragged down the veil, blasphemed and reviled [God]. On his return a mosquito entered his nose and began piercing his skull. And when he died they split open his nose and found that it was like a bird weighing two pounds.
(Genesis Rabbah 10.7; trans. Freedman)
I have highly edited this, removing four of the episodes of death by snake and scorpion and frog, leaving these two fascinating anti-Roman episodes. It is interesting, firstly, that the argument for the importance and purpose of the gnat, the snake, the frog, and the scorpion are the deaths they bring either directly or by assisting other animals to kill an unrighteous human. Power over life and death was, in fact, the prerogative of the emperor (and God). Yet, as bringers of death, the smallest of creatures--even the gnat--can be God's death agent; thus God's agents of death surround us all. The excerpts, however, show something else: the anger at being oppressed, colonized under the Roman imperial regime. In a way, there might be a symmetry between the perceived smallness but real potency of the snake and gnat and the Jews themselves in comparison to the Romans, the destroyed small Jewish commonwealth in the shadow of the great Roman empire. While the emperor has perceived power, the Rabbis claim that even a gnat has the equivalent power of life and death, that they, primarily through Torah study, become agents of God. As the last story illustrates, even a miniscule mosquito can bring down the ruler of the most powerful earthly empire!
I am also interested in how the texts read life-situations in the way they do other texts. These are, of course, fanciful stories, but express a stance of interpretation of life that one can take to scripture--all is relevant; nothing is misplaced. It applies the typical midrashic principle of the school of Akiba (that every little jot and tittle of the Torah has meaning). As R. Eleazar says, "This has a purpose."
While the first anti-Roman story is literally potty-humor--a snake biting and killing while the Roman is in the privy--the second shows a bit of interesting parallelism: just as Titus entered the Holy of Holies, the inner chamber of the temple, dragging down the veil, and ransacked the temple from the inside out, so this little mosquito enters Titus' skull (the inner chamber, so to speak, of his head), eats and ransacks it by eating up his brains. As Titus destroyed the temple, the mosquito pierced his skull.