What kind of brooder do you have? Another poster suggested a wire-sided brooder with the access door on the SIDE, instead of over the top. The birds naturally see their world around them on their level, and instinctively view things (your hands?) hovering or diving in from above their heads as a threat. Always move slowly, no loud noises, coo and talk and cluck to them, handle them frequently, feed treats (scrambled or boiled egg, mealworms, alfalfa hay or sprouts, broccoli - to name some healthy treats for chicks) from your hand. Sit with them on the ground outside. They can go for outside trips within a few days of hatching, if it's warm. Some people brood and grow their chicks ONLY outside. It's fine, as long as they're protected and don't get wet or chilled.