It started with a seal pup... Now US zoos are engaged in a #CuteAnimalTweetOff

The Smithsonian seal pup which triggered a cute animal tweet-off.
The Smithsonian seal pup which triggered a cute animal tweet-off.PHOTO: TWITTER

WASHINGTON - Zoos and aquariums across the United States are doing battle online for who has the cutest animals.

The hashtag  #CuteAnimalTweetOff was created after the Smithsonian's National Zoo sent out a sweet photo of a newborn seal to announce its birth.

Radio host Sarah Hill then tweeted to her favoured Virginia Aquarium that the ball was in its court to up the ante on the cuteness factor and a Twitter battle was born, said an ABC News report.

The aquarium answered with this photo.

Competition between the two was fierce and fast.

"Yep, I instigated the hashtag," Hill told ABC News.

"The National Zoo tweeted out a picture of their adorable new seal pup, and I thought, 'Oh, we have cuter seals than that here in Virginia.'

"So I tweeted it to our aquarium, and they ran with it. Then everyone else jumped on board because, really, who could turn down a cute critter competition?"

Other zoos and aquariums across America noticed and wanted in on the adorable action, blowing up people's Twitter feeds with their most exotic, endearing animal pictures, said ABC.

"I am absolutely overwhelmed by the response," said Hill. "It's so wonderful to take back Twitter for something positive. I thought maybe two or three zoos and/or aquariums would respond, but wow. I'm getting Twitter notifications from zoos around the world showing off their adorable residents. Best day ever."

The animal enthusiast said she hopes the #CuteAnimalTweetOff encourages people to "support their local animal conservation, rescue and rehabilitation organisations."

"I mean, look how happy it's making people," she said.