Bunnies are very social animals and are only entirely happy living as a couple or in a group. One would usually not keep a single guinea pig or parakeet, why keep only one bunny?
What we hear very often is that people are afraid that their bunny will not be as tame once he/she is bonded with a partner. This is not true. After many years of ‘bunny experience’ and a lot of contact with bunny parents all over the world, I’ve never heard that a bunny didn’t want to cuddle after they got a partner.
There are bunnies that like to cuddle, and bunnies that don’t. This sometimes changes during their puberty stage, but if they love cuddling they will love it no matter what.
Bunnies need a partner of their own species to “chat with” and to groom their fur & ears, to cuddle, and to play around with. No human could ever take that place. I like to think of it like spending my life among elephants…it would be fun, but extremely lonely.
Bunnies that have a partner are happier and healthier. After all, they teach each other. If one bunny, for instance, doesn’t like eating a certain veggie then you will be surprised how that will change over time; it is very likely that after seeing his/her buddy bunny munching on something yummy, the other bunny will want that exact same veggie as well.
It is also a big plus to have a partner when one bunny gets ill. Don’t separate them unless necessary because they do “care” for each other, and the sick bunny will have much higher ambition to get healthy again - simply because it wants that carrot the other one has in its mouth!
Bunnies that live alone are likely to develop aggressive behavior, especially if they have to live in a cage. They might even start ripping out their fur.
It is not enough for a bunny to live with a guinea pig, cat, or dog. It’s not the same species and they do not speak the same language.
Guinea pigs are rather noisy at times, which can freak out the rabbits into hurting them. Cats and dogs are also not proper buddies for bunnies. They can make good friends but it should always be kept in mind that rabbits are prey animals - and cats and dogs are predators.