So I don't know what it is, my dog was calm when he first met the chicks & now he's crazy for them. They are a month old & he watches me w/ them out the window like a total creep. Tonight my son let him out, not realizing the chicks were free roaming, & the dog went right for them...seemingly to have a chicken snack. My super mother sense had me yelling the dog's name before anything came even close to happening (he's a good dog who responds to "stop!"), but seriously... steps need to happen to prevent anything from going further. Do dogs & full grown chickens work so much better? I see my friends dogs & chickens co-exsist beautifully. Is it only natural that he is interested? Maybe he wasn't going to hurt them, but he was certainly full speed ahead towards them.