E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Flea
as a parasite.
1
Hobbes clearly proves that every creature
Lives in a state of war by nature;
So naturalists observe a flea
Has smaller fleas that on him prey,
And these have smaller still to bite em,
And so proceed ad infinitum.
Swift: Poetry: a Rhapsody.
Sent off with a flea in his ear. Peremptorily. A dog which has a flea in the ear is very restless, and runs off in terror and distress. In French: Mettre à quelquun puce à loreille. Probably our change of word implies a pun.