Well that depends. If it has a kid, it tends to leave after 24 hours at the next midnight after the baby is born. You can mate tamas together at any age after 3 and catch the matchmaker from 6yrs to 8tys old. In this case, you do see them grow old really they leave their son or daughter in their place and go home. If it does not have a kid, they will grow old and stay with you until they die. Mine that I kept lived to be 21. Many live to be 30 something and sometimes older. Hope this helps
im not sure but what ive heard is that the age goes up to 99 but you could keep caring for it forever. until it dies though. but again, i dont know if this is right.