An escape from an apartment that would have become a cage if they had stayed, because wellness checks would inevitably occur. And wellness checks bring the danger of being discovered and possibly even captured by humans.
Not knowing how to fly is not an excuse. They have to trust those new instincts to help them flee under the moonlit sky, to survive the glide to the ground. The cover of the treeline at the edge of the apartment building’s property is their best avenue of escaping from the place they can no longer call home.
Edited