Ok so this is really weird. So I have exactly 13 zebra finches. Well I originally had 13. I now have 19. I keep my finch cage outside. I sometimes let them out of the cage for free flying which they really love. I do it about an hour before feeding time so I can call them back with food pretty quickly. I don't do this very often but maybe a couple times a month. So about 3 weeks ago I let my birds out for a couple hours before I feed them that morning. I called them back and I made sure I had every one of them. I leave the cage open while they eat because there are always a couple stragglers. And I always count my birds. When I counted them I counted 15 which completely blew my mind! And then another one flew in a couple minutes later. The next day only half of my birds came back on time and then after feeding they all came back with 3 more zebras and like a society finch (I think). I've been living here for a very long time and I have never seen any zebra finches flying around. I hardly see any birds flying around except the occasional robin. I captured the stray birds and they're in the aviary now. I'm kinda scared to let my birds out because I feel like they might go to wherever these new birds came from and stay lol.