So there I was, momentarily speechless after my five-year-old had inadvertently brought up the subject of incest at the breakfast table. But hey, that’s just part and parcel of life with guinea pigs. Not to put too fine a point on it, but a guinea pig would screw its own mother. So it’s important to have guinea pigs sexed correctly, and to house the sexes apart. The RSPCA has guinea pigs at its shelters, as well as rabbits and ferrets. You wouldn’t want to refer to a pet from the pound as second-hand, but with the surrendered rather than rescued animals you can certainly entertain the hope that they are pre-loved.