We adopted two Guinea pigs four years ago. Sadly one of them died last night. Can the remaining one live on his own? We don’t want to get any more now so getting another isn’t an option. If he’s sad on his own we will need to give him away which we’d ideally like not to do. Can Guinea pigs be happy on their own? He is about 6 years old and has always lived with his brother until last night 😢