They slipped into place under the cover of darkness. (desmogblog.com)
Some prey animals such as deer, horses, and cattle also have this visual adaptation so that they can see predators approaching under cover of darkness. (thehappypuppysite.com)
It would be easier to let the sun set on our initial shock and attempts to help and pretend that the problem disappears under the cover of darkness. (nakedpastor.com)