I think the reason peeing/pooping is rewarding is that they can also be painful. If pooping is more painful than not-pooping, an animal might delay pooping for an unhealthy amount of time. They are also activities that take time and require attention, so pooping/peeing when no more-rewarding activity is available is probably a good idea in general.
I think the reason peeing/pooping is rewarding is that they can also be painful. If pooping is more painful than not-pooping, an animal might delay pooping for an unhealthy amount of time. They are also activities that take time and require attention, so pooping/peeing when no more-rewarding activity is available is probably a good idea in general.