Yes it was, in Book 7.
... classroom where Professors McGonagall, Flitwick, and Sprout were standing at a smashed window.
"He jumped," said Professor McGonagall as Harry and Luna ran into the room.
"You mean he's dead?" Harry sprinted to the window, ignoring Flitwick's and Sprout's yells of shock at his sudden appearance.
"No, he's not dead," said McGonagall bitterly. "Unlike Dumbledore, he was still carrying a wand... and he seems to have learned a few tricks from his master."
With a tingle of horror, Harry saw in the distance a huge, bat like shape flying through the darkness toward the perimeter wall.
(Harry Potter and the Deathly Hallows, Chapter Thirty - The Sacking of Severus Snape)