ATLANTA — Panda twins born three years ago at Atlanta’s zoo are set to leave for China later this year.

Zoo Atlanta says Mei Lun and Mei Huan are expected to leave for the Chengdu Research Base of Giant Panda Breeding in November. The zoo says the pair were the first surviving giant panda twins ever born in the U.S.

Their mother, Lun Lun, gave birth earlier this month to another set of twins. She and her partner, Yang Yang, have had a total of seven offspring, all conceived by artificial insemination.

Like at the other three U.S. zoos that have giant pandas, the bears are on loan from China. As part of the loan agreement, all adult offspring are sent to China when they’re of age.