Every few years a vixen creates a den underneath an old shed at the end of our garden. I don't encourage them or feed them, and I keep my distance because I don't want them getting too used to humans or too close to my cat, but I'm happy to let them stay.
During 2016 we actually had two vixens, who each produced a litter: the first of 3 cubs, the second of two cubs. Here you can see both litters play-fighting, sorry for the grainy video it was filmed using my mobile on full-zoom.
One of this year's cubs was particularly cheeky, and despite my efforts to discourage him kept stalking me while I was gardening. In the end I gave up and accepted his company.