third estate for pets (freedom)

As we know, pets have two states, one is still / sitting and the other is following us. And what would it be like to have a third state? I do not want my pets to follow me for fear of losing them but it saddens me to see them sitting all the time. I think that there should be a freedom mode where your pet roams your house in his free will, and in turn, using a copper ingot, a whistle could be created to make him return in case he escapes or gets lost