If the hen is not a good mother, the chicks can be brooded in a separate container with a heat lamp. However, the mother hen provides HUMIDITY for the eggs, so unless you are taking them and putting them in an incubator with the appropriate amount of humidity, the chicks may not make it with the heating pad. There isn't sufficient humidity with that method and the inside membrane will dry up and shrink wrap the chick, causing it to get stuck and die. Hens have been hatching chicks for a long time and sometimes they just need to learn how along with instinct. If the hen is killing them, take them as they hatch, but leave the eggs with her until then.