Australia Funny Piggy Behaviour

I have two examples of funny behaviour the first is that I have built this beautiful big Cavy Cage, and I put a litter box made from a small cardboard box which I cut down and put a box over the top with a hole for a lid, now even though they have this huge cage most of the time they are all cramped up in this litter box, maybe because it's winter and it keeps them warm maybe they just don't want to run and play, I don't know.

My second example involves my Boar named Poppy, (because he popcorns a lot) anyway, I put a beanie in the box for my piggies to sleep in etc, but what do I see when I come home from work? Poppy popcorning around the beanie, then he proceeds to curl up and grasp the beanie with his front paws, and mounts it and begins to (I don't know if I should say it on this site) 'hump' the beanie! Just like a randy dog would! I couldn't believe it! Has anyone else seen this sort of thing? Please post your funny stories.