People email me this question more than any other, and I mean that literally. Not "where can I buy a CD" (the answer is sadly nowhere, lads). Not even "is the cat real" (he is). It's some version of: "BogLord, my granny sang it different — is mine the WRONG one?" And I have to keep telling people, gently, that there is no wrong one. There's just the one you grew up with and then there's everybody else's, which all sound slightly cursed to you the first time you hear them. So. Let me try and lay out every regional variation I've actually heard, sourced, or had screamed at me at a session, because nobody else has bothered to do it in one place and it's been driving me MAD.
First thing to get straight. The Rattlin' Bog is what folklorists call a cumulative song, the same family as There Was an Old Lady Who Swallowed a Fly. It builds. Bog, tree, branch, twig, nest, egg, bird, feather, flea — and back DOWN the whole ladder every verse. That spine is shared everywhere. What changes from place to place is the chain of objects, the chorus, and crucially what comes at the very bottom. (More on the bottom in a minute because that's where it gets gas.)
The Irish version, the one I consider home base, ends on the flea. "On the flea there was a germ, a rare germ and a rattlin' germ" in some versions, but most stop at the flea and that's the CLIMAX, that's the bit you race through trying not to die. Our chorus is the "rare bog, the rattlin' bog, the bog down in the valley-o." If you want the full text I've laid it all out on the lyrics page, so I won't reprint the whole ladder here.
Now. Scotland.
The Scottish version is the one that confuses Irish singers the most, and I had a lovely back-and-forth about this with a few of the Scottish lads in the forum (shout to scottish_peat_morag, who came in skeptical and left converted, which is the dream). Up there it's often "The Tree in the Bog" or just "The Bog Down in the Valley," and a lot of Scottish singers learned it through the Scouts and the folk revival rather than the pub, which gives it a brighter, marchier feel. The chain is more or less the same but I've heard "limb" where we say "branch," and the tune sits a touch higher. Same animal, different collar.
Then there's the one that trips EVERYONE. In a lot of England, America, and the Scout/Guide/camp tradition more broadly, the song isn't about a bog at all. It's "The Green Grass Grew All Around." Same skeleton — hole in the ground, tree in the hole, branch on the tree, nest on the branch, egg in the nest, bird on the egg, and so on — but the bottom isn't a flea, it's "the prettiest green grass that you ever did see," and the refrain is "and the green grass grew all around, all around." First time an American camp counsellor sang me that I genuinely thought he was taking the mick. He was not. It's a real and very old cousin, and honestly it might predate our bog framing — these things are murky and I'm not going to pretend I have a clean family tree, because I don't, and anyone who tells you they do is selling something.
The American "Rattlin' Bog" proper (the one that came back over via the folk revival and groups like the Irish Rovers types) is basically our version sped up and Americanised in the consonants. Same flea, same valley. The difference there is mostly tempo and showmanship — it's a race, a clap-along, an audience-participation set-closer rather than a session ramble.
A few smaller wrinkles I've collected over the years, take them as field notes not gospel:
The Australian/scout camp versions tend to add hand actions for every object, which is chaos and I love it. Some Canadian Maritime singers do a "hair on the flea" extra rung, which is just showing off. rattlin_bog_brasil told me her Irish granny sang a verse order I'd never heard, with the nest and the egg swapped — and you know what, after a few weeks I couldn't decide which was right anymore. That's the song getting into your head and rearranging the furniture.
The thing people miss is that the variation IS the point. A cumulative folk song has no studio master. It's not a recording you're trying to match. It's a living thing that mutates in every kitchen and around every fire, and the "errors" are just regional dialects of the same impulse — to start small, build something ridiculous, and see who falls over first. If you want the deeper background on how the cumulative form even works and where I think ours came from, I went long on it in the history of the Rattlin' Bog, and you'll find the green-grass cousin and a few others sitting in the songbook if you want to compare them rung for rung.
So no, your granny wasn't wrong. Your granny was a regional variation, which is a far more dignified thing to be. Send me yours. I keep a list. The list is getting long and slightly out of hand, which feels appropriate for this particular song.
Slán go fóill, BogLord2002
P.S. — Rattlin sat on the windowsill the entire time I wrote this, watching the cursor like it owed him money. He has heard every version. He is unimpressed by all of them.