In the Scottish nursery rhyme, what does Wee Willie Winkie wear while running around town?

The first verse of "Wee Willie Winkie is:

"Wee Willie Winkie runs through the town,

Up stairs and down stairs in his night-gown,

Tapping at the window, crying at the lock,

Are the children in their bed, for it's past ten o'clock?"

The explanation of the words to "Wee Willie Winkie" was to teach children to associate everyday tasks with their own lives. Before the days of the wireless, television and the Internet, great reliance was put upon the Town Crier to pass on the latest news and information. 'Wee Willie Winkie' was the children's version of the Town Crier. "Wee Willie Winkie" is a Scottish nursery rhyme whose titular figure has become popular the world over as a personification of sleep. The poem was written by William Miller (1810 - 1872) and titled "Willie Winkie", first published in "Whistle-Binkie: Stories for the Fireside" in 1841.

Such was the popularity of "Wee Willie Winkie" that the character has become one of several bedtime entities such as the Sandman, Ole Lukøje of Scandinavia, Klaas Vaak of the Netherlands, Dormette of France and Billy Winker in Lancashire.