After our initial Bob encounter we figured out what there are few of cats who come over to check for food. They mostly come one by one, and look a like, so I am actually wondering if they are relatives of some sort...
One of cats who comes our back yard to get some food, tiny little one at first glance, brought her 4 kittens along for the day (I guess kitten daycare was closed or something). They chilled out in the back yard, played a lot, slept, played again and then left at night. One little one also managed to explore our top patio.