Xenomorph Mystery

This is my 100th post of this year, showing just how little I posted last year and how much I have posted during this one. Today I watched the film Aliens after watching Alien last week and something struck me as odd. Why have the Xenomorph aliens travelled without viable hosts? The aliens (binomial names are Internecivus raptus and Linguafoeda acheronsis  which mean "murderous thief" and "foul tongue from Acheron" respectively) have a multi stage life cycle. They begin as eggs laid by the queen (they are eusocial) and from these hatch a parasitic stage known as a "facehugger" which attaches itself to the host and impregnates them with embryos. These embryos gestate within the host, absorbing some of its DNA. Due to this process, the Xenomorphs vary dependent on their hosts. Within the films there are mostly human based aliens, though dog Xenomorphs are seen and there is a Predator version too.

From the embryos form what is known as a "chestburster" as it kills the host by leaving its body violently through the chest. Within hours it moults and grows into the adult form.

As they require a host for the facehugger, why did the ship seen in the first two films not contain any viable hosts? There were thousands of eggs, so did they simply lay dormant waiting for any hapless victims? It would be such an odd strategy when a few hosts taken with them would have been useful. Obviously in order to evolve they must have had viable hosts on their home planet.

This perplexed me and has me wondering about their evolution as well. It can be quite interesting trying to work out how science fiction creatures evolved, especially as they were not often designed with evolutionary plausibility in mind. Perhaps that is something I can put my mind to in future. I already have in mind to write a hypothesis about the evolution of the creatures in Tremors, which has been done already but I might do a competing hypothesis based on the same data, just for a laugh.

Whilst looking for images for this post I found some interesting pictures. Click here to see a CG image which is not safe for work and is strong evidence of the truth of "Rule 34". Below is an awesome chess set I found: