Last week we last 3 week old two chicks after they showed the following symptoms: eyes closed, lethargic, huddling together, ruffled feathers, and eventually just laying around. Our neighbors gave us two more chicks. A week later, one of them has the same symptoms again. They are in a box with 6 other chicks, around the same age. I'm wondering if I should separate sick one and give it antibiotics, or should I give them all antibiotics, even though they are not showing symptoms again. Thanks!