The Rattling Bog

Whilst searching for articles on fleas, I came across this old Scottish song, The Rattling Bog.

Things start getting interesting around verse 9

Now on this feather there was a flea.
A rare flea. A rattling flea.
Flea on a feather.
Feather on a bird.
Bird on an egg.
Egg in a nest.
Nest on a twig.
Twig on a branch.
Branch on a limb.
Limb on a tree.
Tree in the bog
And the bog down in the valley-o.