Wish there was a spray for ‘em.
Watch out for drama queens. Drama belongs in front of the camera, not behind it. If they are indispensable, contain them severely. If they are not indispensable, dispense with them.
Make it a reasonably nice dispensing, but don’t worry about how they’ll interpret it — they’re drama queens and they’ll freak out because that’s what they do. Just get them off set ASAP.