Answer
This short poem shows the order of a flea. The poem states that big fleas have small fleas that bite them, those smaller ones are then bitten by even smaller fleas and it goes on and on.
It is just like a fractal image in which, a shape is subtracted from within the image and even smaller image is then subtracted from that image and it goes till infinity. So, the order of a flea explained in the poem is just like a fractal image.
