I acquired 4 bantam chickens (2 silkie hens, a cochin roo, and a frizzle roo of some sort). They are used to being free so they just fly out of the run every morning and fly back in to roost every evening. A few days ago the frizzle disappeared. There was no feather laying around or anything. He just vanished. These birds never wonder far from the run and hang out under our trailor much of the day. They also have access to the always open barn. Last night one of the silkies disappeared. Again, no sign of it anywhere! I went out to give all the birds treats around 4PM and when I went out to water and shut everybody up for the night, she was gone. What could be taking the birds? My dogs don't pay attention to the birds and there aren't any other dogs around. We don't live by any woods, just fields. Closet neighbor is about 1/2 mile away. Any ideas?