Amazing Nature: Slug On Styrofoam

How did this garden slug (a terrestrial, shell-less mollusc) get on this styrofoam cooler in the basement? I "hate" styrofoam but an RX delivery came in it and I don't know what to do with it. And this slug . . . not cute and cuddly but a complex, living creature. And at the end of the video it pulls in quickly . . . obviously aware of me, too. Amazing. "Lake Music" from the album, Eolian Minstrel : ) Comments Welcome