From the annals of interesting human/non-human animal relations, here's a unique way in which people are interacting with pets: as match-makers for grieving and lonely rodents.
Seriously, I couldn't make this stuff up.
It turns out that Switzerland has a law requiring guinea pig owners to keep more than one guinea pig, since these are social creatures and shouldn't be lonely. When one animal dies, however, some owners don't want to replace it with a younger animal, lest they be trapped in a never-ending spiral of rodent replacement. So, they "rent" guinea pigs from a woman who loans them out for that purpose.