Having two sets of eyelids, an inner and an outer, we can close one or both at will.

The inner one is a thin skin that we blink with, and draw across our eyes in the day-time when the light annoys us, just as House People pull down a curtain to shut out the sun.

The outer lids we close only in sleep, when we put up the shutters after a night's work, and at last in death--for birds alone among all animals are able to close their own eyes when they die.

The other habit is the trick of turning our heads entirely round from front to back, without wringing our necks or choking to death.

This we do to enable us to see in every direction, as we cannot roll our eyes about as freely as most birds do.
"Come to think of it, I am very fond of eating one bird that, so the Wise Men say, is as bad as a mouse for mischief.