Mark but this flea, and mark in this How little that which thou deny'st me is; It sucked me first, and now sucks thee, And in this flea our two bloods mingled be.

-Donne,John
c.1595^1605  'The Flea', collected in Songs and Sonnets (1633).

Sir, there is no settling the point of precedency between a louse and a flea.

-Johnson, Samuel known as Dr Johnson
  On the relative merits of two minor poets. Quoted in James Boswell The Life of Samuel Johnson (1791), vol.4.

To produce a mighty book, you must choose a mighty theme. No great and enduring volume can ever be written on the flea, though many there be who have tried it. 564

-Melville, Herman
Moby Dick, ch.104.

If I be evil intreated, or sent away with a flea in mine ear, let him look that Iwill rail onhimsoundly; nor foranhour or a day, whiles the injury is fresh in my memory; but in some elaborate polished poem, which I will leave to the world when I am dead, to be a living image to all ages of his beggarly parsimony and ignoble illiberality.

-Nashe,Thomas
  Pierce Penniless, His Supplication to the Devil, 'An Invective Against Enemies of Poetry'.

English literature's performing flea.

-OŁ    Bruadair, Da¤ i bh|¤  dh
Of P G  Wodehouse. In P G  Wodehouse Performing Flea (1953).

   So, naturalists observe, a flea Hath smaller fleas on him prey; And these have smaller fleas to bite 'em, And so proceed ad infinitum. Thus every poet, in his kind, Is bit by him that comes behind.

-Swift,Jonathan
  'On Poetry', l.337^42.