Mate of mine was bivvying up by Sprinkling tarn in the Lakes.
He was nicely tucked up in his bivvy bag when he heard what he later described as "evil noises" outside in the dark. Being a big brave boy he did the courageous thing - he cowered in his bag, and waited for whatever it was to go away.
In the morning he unzipped his bag to find the contents of his rucksack strewn across the fells - the local Herdwicks must have smelled the bread he'd got in there for making toast for breakfast, and had rummaged their way into it, scattering stuff all over the place in the process . . . .