Why Susan Sarandon’s Dog Started Tweeting

Susan Sarandon and dogs Penny and Rigby visit Late Night with Jimmy Fallon

Lloyd Bishop/NBC

updated 04/26/2013 AT 1:00 PM ET

originally published 04/26/2013 AT 3:30 PM ET

Like any working actress, Susan Sarandon’s dog tries hard to stay current. So now, she’s entered the digital age, trying her hand – er, paw – at social media.

“She felt after she watched Melancholia that she had to reach out,” The Big Wedding star joked on Thursday’s visit to Late Night with Jimmy Fallon of why her Pomeranian/Maltese mix, Penny, decided to create a Twitter account. “She Tweets from where we are.”

But while Penny’s visit to Late Night, alongside pooch sibling Rigby, may have given her more material for her feed, it left Fallon and Sarandon scrambling to keep her calm, as Penny frequently jumped out of mom’s lap and ran around the studio.

“You know she’s going to poop on the set,” Fallon intoned, while Sarandon added, “This is why she didn’t get the part in The Big Wedding.”

After the future Tonight Show host pulled out a toy monkey and palled around with Penny a bit on the floor, she seemed to calm down – before turning her sights, and growls, onto Rigby.

“They’re turning into demons,” Fallon said, wondering, “Is it my voice?”

Despite the hijinks, though, no one was worse for the wear.

“Rigby and I ‘high jacked’ Jimmy Fallon tonight and he seemed to enjoy it!” Penny later Tweeted. “What a good sport. I had fun. U tell me when u see it if he did.”