I have wondered about this aswell.And my thoughts go deep into this subject
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OK;Let me fathom this again:
1.)Queen lays eggs...{check}
(2.)facehuggers are a development from the egg,,and thus Impregnates host with yet another one...{check}
(3.)Alien is born via-host...{check}
Ok cycle is complete
No its not
BUT WAIT A MINUTE!
How did the Queen get seminated in the first place to produce the eggs??
Simple,And we can go on arguements about A-sexual beings.but for practical Deductions,I have Figured that aliens are not so complicated as we make them.The queens are female with reproductive organs,and the other aliens are male with male reproductive organs.