Even the Magic Kingdom is nervous about terrorism.
Metal detectors debuted Thursday at the entrances to Walt Disney World, Universal Orlando and Sea World.
Disneyland and Universal Studios in California are also using the devices.
Following terror attacks in Paris and San Bernardino, the amusement parks have stepped up security as fears festered of killings erupting in crowded public places.
On Wednesday, the Department of Homeland Security warned people to be more vigilant at "public events or places."
Disney World said Thursday that it was discontinuing the sale of toy guns and banned costumes for visitors older than 14, the Orlando Sentinel reported.
A man was arrested last week when he tried to enter the park with a handgun, authorities said.
Police dogs are also being used at Disney World to patrol areas such as the monorail, the paper said.
"You're going to wait in lines all day long, so what's one more line," park patron Tim Harden, 24, told the Sentinel.
Six Flags parks have been using metal detectors since the Sept. 11, 2001 terror attacks.