1.5 -2yrs yrs old. All aros will jump. I agree with that but these have never attempted to in this pond. They obviously have tons of swimming room. As mentioned before, I did put a net cover on the entire pond and they majorly freaked out to a point of me removing it. Hence no cover and they are so much calmer. I think its due to the large swimmng area and being hand fed all their life.