The Chestburster (aka burster) is a Xenomorph larvae or Baby Alien. Its egg is laid in the host's bronchial tubes by a Facehugger, where it hatches. It then burrows for the host's aorta (major artery in the heart), where it feeds on absorbed nutrients and white blood cells. After about an hour or two, it lets go, and begins swimming about in the host's body, causing mild discomfort at times. It can take from 1-24 hours after it lets go, for it to become large enough to leave the hosts body. It then finds the sternum, and starts chewing. This causes the victim great pain, shock, and blood loss. Then, true to its namesake, it pops out, and finds a nursery, chicken coop, or, less messy, a food locker, something with a large amount of helpless meat.