In bruising the heel of the Woman's seed, Satan can only accomplish his purpose through humans. Like he did through Adam and Eve; and Cain and Abel etc.

.............................There was conflict between Satan and the Woman and her seed down through the ages, which reached a great point at the beginning of the New Testament Age.

................At that time Israel gave birth to the Manchild Christ and Satan making desperate attempts to destroy Him.

Read Galatians 4:4