They come out at night at about the same time as the humans take shelter in their houses.  This is the deal, learned over time.  The domain of night belongs to the wild creatures, the predators and the prey.

Here in the deserts north of Phoenix, coyotes are at the top of the food chain, bowing only to the mountain lions that are fierce, unseen, and lightening quick solo hunters.  The coyotes couldn’t be more different.  They love to talk, and call, and chorus, and hunt in coordinated packs.  Humans are respected in daylight.  At night, they would be a juicy meal.

Coyotes : Night Callers