Rabbits have more personality and make better companion pets. They also have more complex needs, so guinea pigs are less of a responsibility than rabbits. If you have time and can adhere to a schedule, rabbits are an excellent company. Guinea pigs are less demanding family pets. Guinea pigs are a little more fragile than rabbits, and so are more suitable for older children. Younger children (under constant adult supervision) can handle a lot of different rabbit breeds. Rabbits do have more neurons in their brains than guinea pigs do. This should have made them smarter and more intelligent than guinea pigs.