Happy Birthday

Animalcules.

If the dog has fleas does not the flea have fleas?

That phrase is in my head but the closest I can find quickly is Swift's, and below that, this:

"Great fleas have little fleas upon their backs to bite ’em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on.
De Morgan: A Budget of Paradoxes, p. 377. [back]"