How do you breed your pet in petz nursery?

what u have to do is get two dogs tohave three hearts (by petting them ALOT) then, you have to put them in the same room they will start to like each other. then they will have only one puppy
have a female and male all grown up.......make them have a happy happy face....leave them in a room together and when you see hearts around them you have a puppy