This could be our moment, panda fans. The National Zoo said Friday afternoon that its expectant giant panda, Mei Xiang, is likely in labor.
She "has become increasingly restless and began body licking—both signs that labor has probably started!" the zoo shared in a tweet.
The zoo's giant panda team is closely monitoring the zoo's Panda Cam to watch for the delivery of a tiny cub.
The big news comes just a week after the zoo announced they had detected a possible panda fetus on an ultrasound of Mei Xiang, but panda fans were told to temper their expectations. However, on Monday, the zoo shared that a panda fetus was seen "kicking" and "swimming" during an ultrasound that morning. "We hope to have a healthy cub in the coming days!" the zoo said at the time.
On social media, the zoo shared a short video clip of the fetal cub wiggling on during Monday's ultrasound and told followers, "Keep your paws crossed!"
Mei, now 22, has previously given birth to three surviving cubs: male Tai Shan in July 2005, female Bao Bao in August 2013 and male Bei Bei in August 2015. All three now live in China, per an agreement between China and the U.S. The youngest of the three, Bei Bei, departed for his new life in China just last fall.
Photos: See Bei Bei Grow From Cub to Giant Panda
All three cubs elicited major celebration when they were born. But there's been heartbreak along the way as well.
In 2012, ending a seven-year gap after the birth of Tai Shan, Mei finally had a second cub, but it lived just a week. The following year, Bao Bao arrived, but with a stillborn twin. And Bei Bei was also born with a twin, but his brother lived only four days.
This March, Mei was once again artificially inseminated with semen from the zoo's resident male giant panda, Tian Tian. Although it's been months since then, pandas experience what's known as delayed implantation. When fertilization occurs, an embryo doesn't attach to the uterine wall until weeks or months later.
The panda house at the National Zoo is currently closed to provide a quiet environment for Mei Xiang. You can keep up with the pandas 24/7 on the zoo's panda cams.