We have a husky who stays outside at night (she prefers it that way).
She is a mountain dog, un-phased by deer or elk, giving a quick warning growl to raccoons to stay away from the chickens. (Unlike the chocolate lab, who barks hysterically at TREES). So, when she starts barking wildly in the middle of the night, we know it's a bear or mountain lion.
Or a bug.
(To be fair, a big bug. With a furry backside. I feel ever so much safer.)