Ellen Page Reveals Secrets of 'X-Men: Days of Future Past' Sentinels (Video)

Also on Tuesday's late night TV roundup, Seth Rogen and Zac Efron join Jimmy Fallon for "Ew!"

Ellen Page shared one fear with Seth Meyers about working on the special-effects driven X-Men: Days of Future Past.

The actress, who appeared on Late Night on Tuesday, said that when shooting the film she acted opposite "a tennis ball," which stood in for the mutant hunting robots. "But I have a phobia of tennis balls, so it works really well," she quipped.

Meanwhile, on The Tonight ShowJimmy Fallon welcomed Neighbors stars Zac Efron and Seth Rogen for a very testosterone-filled session of "Ew!" The girls even got a text from James Franco. (Ew!)