Some pets should interact with each other, like moving close to them or some of the more aggressive pets to attack one another. Like panthers against jaguars, panthers against panthers, etc. They won’t kill each other, but they’ll just play around. It can start with the predators growling, and then they’ll start slashing and wrestling. Lions, tigers, and bears, oh my! And even if deer or the like aren’t aggressive towards you, they will lock antlers and fight each other.
And I know we don’t have a hunger system anymore - even if I think it’d be interesting to have an option - animals will gather around a feeding box and begin to eat from it. They’ll go to the box and leave periodically.