* FairForItsDay: For the most part, in its depiction of the younger Dr. Medford, the film was positively enlightened. She's a competent professional who ably assists in dealing with the film's giant mutant ants, including going down with the male (non-scientist) heroes into a gassed colony to make sure the inhabitants are all dead. She does scream once, when she abruptly and unexpectedly comes face to face with one of the creatures, but beyond that moment she also never falls into the DistressedDamsel catagory.
* NightmareFuel: The ants can be this, depending on your view. As well as the blood-red title (in the actual film, no less) and [[FridgeHorror implications of the first scene.]]
** The trailer as well. "...with things so horrible...so terrifying...SO HIDEOUS! There is no word to describe ''THEM''."
* NothingIsScarier: Much of the beginning of the film shows only the aftermath of the ants' attacks. We see only the damage they have caused and a few bodies, one of which is filled with acid and chewed to bits. This helped build up their menace prior to them turning up on screen.
* OneSceneWonder: Fess Parker as the pilot-witness; landed him his role as Davey Crockett.
* SpecialEffectsFailure: Compared to today's slick CGI, the ants look dated, but the giant models were impressive for their time, albeit slow-moving. One reason most of the following giant-thing movies were so bad is that pretty much all of them used clumsy super-imposed images to serve as the monster.
* TearJerker: When the little girl goes hysterical, you can't help but realize the poor kid is probably remembering her family being slaughtered right in front of her. Heartbreaking.