The Smithsonian's National Zoo is home to two new twin pandas. The mother, Mei Xiang (may-SHONG), gave birth to the cubs at 5:35 p.m. and 10:07 p.m. EDT on Saturday (Aug. 22). Mei Xiang can take care of only one cub at a time, so while one cub is with Mom, the other rests in an incubator at the zoo. After about 3 to 4 hours, the zookeepers switch the cubs, giving the newborns equal time with Mei Xiang. [Read the full story on the twin panda cubs]

Tape measure

Zoo staff measure the second-retrieved cub. When the cub isn't spending time with its mother, it rests in an incubator at the zoo and feeds on a special formula made out of water, human baby formula and puppy formula. (Image credit: Devin Murphy, Smithsonian's National Zoo)


First exam

The second-retrieved cub squirms as a team examines the animal's weight, length, mouth size, heart rate and breathing rate. (Image credit: Pamela Baker-Masson, Smithsonian's National Zoo)


A star is born

The second-retrieved cub already has tiny claws, but still has a lot of developing to do. (Image credit: Pamela Baker-Masson, Smithsonian's National Zoo)


Squealing cub

Giant pandas give birth to twins about 50 percent of the time. However, the mother can only pick up and care for one twin at a time, so zoo staff are helping both cubs survive by rotating them from their mother's den to the incubator every 3 to 4 hours. (Image credit: Pamela Baker-Masson, Smithsonian's National Zoo)


Open wide

Veterinarians examine the first retrieved-cub's mouth with a light. (Image credit: Pamela Baker-Masson, Smithsonian's National Zoo)


Swaddled panda

Veterinarians swaddle and examine the first-retrieved cub. Its sex won't be determined until a later date. (Becky Malinsky/Smithsonian's National Zoo)


Heartbeat

The veterinarians check the heartbeat of the first-retrieved cub. (Photo credit: Pamela Baker-Masson, Smithsonian's National Zoo)


The birth

Giant panda Mei Xiang delivered two cubs on Aug. 22. Her water broke at 4:32 p.m., and she gave birth at 5:35 p.m. EDT. After giving birth to the first cub, Mei Xiang picked it up. (Image Credit: Panda-Cam-11 (8_22_2015 5_36_04 PM) )


Panda ultrasound

Veterinarians used panda sperm to artificially inseminate Mei Xiang in April. An ultrasound in late August showed what veterinarians believed to be a fetus. However, it was still unclear whether Mei Xiang was having a real or a pseudo pregnancy, in which her body would act like it was pregnant even though it wasn't. (Image credit: Smithsonian's National Zoo.)

Follow Laura Geggel on Twitter @LauraGeggel. Follow Live Science @livescience, Facebook &Google+