It's..... The happiest blog on earth
Nearly 500 years ago, Little "Bo Peep" was told of her sheep to "Leave them alone, and they'll come home, and bring their tails behind them." But there are actually five verses to the poem, which explain what happened next (and why the syntax was so garbled in the first verse).
Then up she took
her little crook,
Determined for to find them;
She found them indeed,
but it made her heart bleed,
For they'd left all their tails behind 'em!
It happened one day,
as Bo-peep did stray
Unto a meadow hard by--
There she espied
their tails, side by side,
All hung on a tree to dry.
She didn't know where to find them, but was told to leave them alone and they'll come home, dragging their "tails" behind them.
And the final verse makes more sense as a description of a dutiful British customs man assessing the abandoned booty.
She heaved a sigh and wiped her eye,
And over the hillocks she raced;
And tried what she could,
as a shepherdess should,
That each tail should be properly placed...