Reproduction

Reproduction is the biological process by which new, individual organisms are produced. Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction.

Yanme'e Reproduction
Due to their insectoid bodies and use of Queens and Hives, it can be assumed that there is a dominant class within Hives. Like Ants, it may be that Yanme'e Queens produce fertile and infertile descendants. The infertile decedents would be used as Workers and Soldiers, whilst the fertile Yanme'e would be used due create more hives and keep the Yanme'e species ongoing.

Sangheili Reproduction
Little to nothing is known about Sangheili reproduction, apart from the fact that Sangheili have no external reproductive organs. This could leave many things as a possibility, such as having internal sex organs, or even being asexual.

Lekgolo Reproduction
Lekgolo and to an extension Mgalekgolo are not referenced through out all books and games in the halo series, and as such most details are sketchy and based upon assumptions. Despite their being aliens, their appearance is roughly worm like and as such it is assumed that they reproduce in the same manner as worms; which is done by manner of being asexual. However Lekgolo are of alien autonomy, and as such they may reproduce through completely different, unknown method.