Last night the Smithsonian National Zoo's giant panda Mei Xiang gave birth to a baby cub.
It was a magnificent surprise, considering the zoo didn't even know Xiang was pregnant.
The zoo had artificially inseminated Xiang in April, but it's difficult to know if a giant panda is pregnant or not.
Dennis Kelly, the zoo's director, told CNN, "We are thrilled that Mei Xiang had a successful pregnancy."
He also said no one had actually seen the baby. The zoo's staff reportedly heard the cub inside Mei Xiang's den.
"I'm cautiously optimistic as we haven't seen the cub yet," Kelly said. "But we know that Mei is a good mother. Like everyone else, I’m glued to the panda cam for my first glimpse of the cub!”
The time of birth was marked at 10:46 pm, according to the Washington Post, which spoke to zoo curator Becky Malinsky, who first head the cub while watching the zoo's 24-hour panda cam.
Until Sunday Mei Xiang had what the Guardian called 5 "pseudopregnancies" (whatever that is). They said she was given less than a 10% chance of being pregnant.
Not since 2005 had Mei Xiang successfully carried a baby to term.