David explained some of the military techniques he's picked up while filming, and revealed what happened when a stunt didn't go quite as expected.
(Hint: His acting got a little too realistic.)
Stephen pulled out a classic photo from David's past, and the actor shared the real reason why he hasn't slowed for a break between his hit TV roles.
Hey, it helps when you can mellow out to the Grateful Dead.
WATCH: David Boreanaz Is A Deadhead
David's new military drama explores the roles of two families that Navy SEALs have: the one they leave behind and the one they fight beside.
WATCH: Preview Of The SEAL Team Series Premiere
SEAL Team follows the professional and personal lives of the most elite unit of Navy SEALs as they train, plan, and execute the most dangerous, high-stakes missions our country can ask of them.
David's character, Jason Hayes, is the respected, intense leader of the Tier One team whose home life has suffered as a result of his extensive warrior's existence.
READ: David Boreanaz Has Some Serious TV Cred
Watch all-new episodes of The Late Show with Stephen Colbert weeknights at 11:35/10:35c on CBS and CBS All Access.
Watch all-new episodes of SEAL Team on Wednesdays at 9/8c on CBS and CBS All Access.