We live on a ground floor apartment and there have always been a fair number of cats in the area. In the past they just walk by on top of the fence and we think nothing of it. However, in the past week things have gotten really weird. It started with one tabby coming to our patio door and meowing at me. I opened it up expecting it to bolt or just to give it a pet and instead it walked right in, immediately claiming me/the area. Over the next week it kept coming back up to 6-7 times a day. Finally we broke down and fed the poor thing and it essentially moved in with us staying for the past few nights. We let it out whenever it wants but it never leaves for more than an hour. We figured it was abandoned. The strange part happened today when the cat was meowing at the door, this time from the inside. I figured it just wanted out but instead a second tabby cat comes running in. The second cat makes itself right at home, eating/drinking and snuggling up in a cat bed we bought. I'd seen the second cat following the first before and they get along well so we're thinking they know each other. Then only a few hours later a 3rd cat shows up meowing at our door, rolling around outside. We've seen this cat around a lot and it's very skittish. the other cats were really interested so we opened the door. It immediately comes in and, while not friends with the other cats (dominance displays from the first cat and submissive from the third), it lays down on the carpet and hasn't left for about half an hour now. There's also been a fourth black cat hovering around but runs away whenever the door is opened. What the heck is going on!?