OK, I already said my basic view in the quote Terenia provided, so I'll just give my thoughts on what a few others have said.
i think that yeerks are quite capable of love but like the others before me said its just rare.
I think that culturally it would be hard to love if your whole thing is enslaving races. Its considered treason to fall in love with your host remember?
Yeah it would be treason, but I don't see why that would make it rare for Yeerks to love each other. After all, most people here will be capable of love, but probably won't extend it to the same degree to another species. Doing so, certainly in a romantic way, would be socially unacceptable in most if not all human societies, too. I guess it's similar with Yeerks.
Yeah, I'm fairly sure that Yeerks are genderless, but may develop an affinity for a specific gender through hosts.
As far as the love thing is concerned, I think it's obvious that Yeerks can love...but why do we only ever see love between two Yeerks? It takes three to make grubs. Perhaps there is a difference between companionship-love and procreation-love, which would theoretically come later in life when the Yeerk is prepared to die?
Yeah, I agree totally. After all, there is a difference between platonic and romantic/sexual love in humans too: there's friendship, parent-child and sibling love which are all very different to romantic love. I don't see why there wouldn't be that divide in Yeerks.
Just wonder with this. Was Visser 1 female or male. Because she had predominately female hosts but is later referred to as he. I never really understood yeerk gender relations. Maybe it only occurs when they are in a host. Otherwise I think they are hermaphodites. Remember it takes 3 yeerks to reproduce.
Yeah, they are probably genderless (although theoretically the three Yeerks thing could be 2 males and 1 female or suchlike, I imagine they are genderless). I think V1 was a special case, as because she had identified so closely with humans, so at least at times she thought of herself as female. Certainly I imagine that was how she felt during her year on Earth with Essam, although she may have suppressed that later. Likewise, I imagine SV51 in number 33 identified herself as female, as she and Taylor were so closely interlinked and there was quite a bit of confusion between the two.