Answer:
We travel much, yet prisoners are, and close confined to boot. Yet with any horse, we will keep the pace, and will always go on foot.
I am the hole in the night, the ever watchful eye. I return in a cycle, to enlighten the sky.
The more holes you cover the lower it goes.
Two in a whole and four in a pair. And six in a trio you see. And eight's a quartet but what you must get. Is the name that fits just one of me?
What has a single eye but cannot see?
I break away from my pack. I create holes in my victims. I can travel for miles and then disappear. I am part of a dying breed. What am I?