After
a period of three to four hours, the Foetus has absorbed and assimilated enough
of the hosts' bodily nutrients to trigger its accelerated metabolism and rapid
cell division. Once the creature has grown to the maximum size allowed by the
thorasic cavity, it prepares itself for birth. This involves re-locating the
head beneath the sternum and exerting tremendous pressure, secreting acidic
compounds and breaking down the structural integrity of the bone and musculature
imprisoning it. Whilst biting its way to freedom, the host is killed.