None of the moths seen in the film are actual Death Head moths. In the interest of avoiding the hassle involved with actually shipping moth eggs over, then halting filming so they could be raised to the proper level of maturity, the production crew simply went with a similar looking domestic breed of moth, and glued false fingernails painted with the trademark skull like visage onto their bodies.
The Silence of the Lambs is the only horror movie ever to win the Oscar for Best Picture.
The late Gene Siskel was one critic who was not overly impressed with the film. When Anthony Hopkins picked up his award, he jokingly proclaimed, 'What's Gene Siskel's address? Someone give it to me please? I'd love to visit him. I'll see you soon, Gene.'
The female dead body in the funeral home was a real actress, not a mannequin. Because the bug cocoon would be placed in her mouth until it is taken out in the middle of the examination, the prop master made the bug cocoon out of a mixture of tootsie rolls and gummie bears. This way if she accidentally swallowed it, it wouldn't do her any harm.
Hannibal says "I ate his liver with some fava beans and a nice chianti." He could get treatment with drugs called monoamine oxidase inhibitors - MAOIs, which he'd know, being a psychiatrist. However there are things you can't eat when taking MAOIs (potentially fatal), including liver, beans, and wine (also aged cheeses, if you're interested). So he's subtly letting on that he's not taking his medication, through the medium of a joke for his own amusement.
FBI agent John Douglas made Scott Glenn (the actor who plays Jack Crawford) cry, when Glenn was at the Behavioral Sciences Unit (now called Investigative Support Unit) in Quantico, Virginia. He played a tape (sound, not video) of killers Lawrence Bittaker and Roy Norris torturing, raping and killing young girls (between 13-18 years old) in the back of their van. Before the encounter, Glenn was firmly against capital punishment.
During the film's production, while Anthony Hopkins was playing Hannibal Lecter, Brian Cox (who played the character in "Manhunter") was playing King Lear at the National Theater. Ironically, during the production of "Manhunter" five years earlier, Hopkins was playing King Lear at the same theater.
The role of Hannibal Lecter was originally offered to Sean Connery, who turned it down.
Director George A. Romero appears as the bearded man who accompanies Dr. Chilton and two guards to escort Clarice out after she sneaks in to see Dr. Lector.