In his blockbuster movies, he seems to be fearless, but what's the one thing Will Smith said terrifies him? Mice.

"I'm brave for my kids and strong, but if there's a mouse, Jada gotta deal with it," he joked. "Rats are okay, or a possum – but a mouse, ahh! Even now I'm getting nervous thinking about it."

Ellen asked, "Have you ever held a mouse?" -- leading him to look over his shoulder, expecting a scare.

"I'm good with snakes," he explained. "Willow has a boa constrictor… but mice? Whew!"

Looks like we know how to scare Will next time here's here!

In other news – Will's son Jaden explained he is not trying to emancipate himself from the Smith home. "The thing that people don't get is everything at his house is free, so I can get anything and everything I want at his house," he joked. "So I think I'm gonna be there for 20 or 30 more years!"

So where'd the rumor come from?

"I think I made a joke in Tokyo [at a press conference]," said Will. "My baby boy, he's never leaving me, ever!"