Guinea pigs needs to be kept in large accommodation, large enough for them to run, stretch out fully and exercise. They are a prey species and so require a place where they can rest and feel safe and secure. They are not very agile and not good climbers, so take care when adding enrichment to their environment.
Guinea pigs should also be protected from extreme temperatures such as very cold or very hot, they should be kept out of direct sunlight in the summer and kept indoors if the temperature drops below 15 degrees centigrade. Guinea pigs like wooden toys to chew on to prevent their teeth from overgrowing so avoid putting in plastic toys, as they could get swallowed and harm the guinea pig.
Much like rabbits, the majority of a guinea pigs diet should be hay and grass. But they must also have a sufficient amount of Vitamin C in their diet so sometimes this should be added to a small portion of dry guinea pig food to ensure that they are getting all nutrients required. Guinea pigs are also naturally sociable and prefer to be with another guinea pig. However, if you are mixing the same sex guinea pig un-neutered guinea pigs can display aggressive behaviour towards each other, and mixing male and females will result in breeding and un-wanted litters. So please neuter your guinea pig to prevent this from happening. Neutering can be carried out from 6 months of age.