How to count sheep.
Yan tan tethera
by Marnanel Thurman
Before the English arrived in Great Britain, a Celtic language akin to modern Welsh and Cornish was spoken throughout the island south of the Forth. When the English arrived, the culture and language was pushed to the far edges (they "drove the Britons westward into Wales and compelled them to become Welsh", as Sellar and Yeatman so memorably put it), though recent genetic studies indicate that it was more that the culture moved than the people.
And Wales and Cornwall are still with us. But for a few centuries more there was a Celtic holdout north of the Humber, sandwiched between the Angles below and the Picts and Scots above. The old Welsh poems and songs call it the Hen Ogledd, the Old North. It faded away in the end, but one of its particularly interesting relics are the names of numbers used to count sheep:
Yan, tan, tethera, pethera, pimp,
sethera, lethera, hovera, covera, dik.
The names of the numbers are startlingly similar to modern Welsh.
I first encountered this counting system, long before I was aware of its interesting philology, in a book called The Tovers by Elisabeth Beresford. And this is, as you may have guessed, partly where the name of Yantantessera the cat comes from. After all, there's safety in numbers.