Luke 8:33

Then went the devils out of the man, and entered into the swine; and the herd ran violently down a steep place into the lake, and were choked.

Since the man appeared to have a rational interval, Jesus asked him his name. The poor man being the victim, not only of one or of a few devils, answered accordingly that his name was Legion, thousands of demons having taken possession of him. But the devils were growing restive, knowing that their time for torturing this man was over. And so they pleaded with Christ not to commit them to the abyss, to the pit of hell. But there was a herd of many swine feeding on the side of the mountain, within easy distance of the place where Jesus had landed, and the devils eagerly begged Christ to permit them to enter into the dumb brutes. And when Jesus had given permission, the devils took possession of the swine. And the brutes, taken with a sudden spasm of fright, bolted down the precipice overhanging the lake, leaped down into the waves below, and were drowned, suffocation taking place in the water. Note: The devil is a murderer from the beginning. If he cannot destroy the souls of men, he tries to harm their bodies, and when this is denied him, he takes out his spite on the dumb animals. His one desire is to ruin the works of God. But he can do this only with God's permission. It is indeed a secret of God why He gives this permission. But it may be said, in general, that even such visitations, by which the devil works harm against us, are fatherly visitations of God, by means of which He wants to chastise us and call us to repentance.