The sound was blood-curdling in a way.

He had heard nothing like it before in all his life; it almost made one shiver to think of going outside.

The chorus kept up for fully a minute.
Then it began to die out, and David could hear the chill clink of chains.

Through it all Thoreau was grinning.
"It's two hours over feeding time for the foxes, and they know it, m'sieur," he explained to David.

"Their outcry excites the huskies, and when the two go together--_Mon Dieu_! it is enough to raise the dead." He pushed himself back from the table and rose to his feet.