Them! (1954)

In the New Mexico desert, Police Sgt. Ben Peterson and his partner find a child wandering in the desert and sooner they discover that giant ants are attacking the locals. FBI agent Robert Graham teams up with Ben and with the support of Dr. Harold Medford and his daughter Dr. Patricia 'Pat' Medford, they destroy the colony of ants in the middle of the desert. Dr. Harold Medford explains that the atomic testing in 1945 developed the dangerous mutant ants. But they also discover that two queen ants have flown away to Los Angeles and they are starting a huge colony in the underground of the city. When a mother reports that her two children are missing, the team and the army have a lead to follow. Will they arrive in time to save the children and destroy the colony?

Them! is one of the precursors to Godzilla, detailing one of cinema's first and best radioactive monsters. A mysterious rash of killings in Arizona has police baffled. After calling in some scientists, they uncover a massive colony of giant ants, mutated by years of exposure to radiation from bomb tests. As the beasts attack the town, two queens hatch in the nest and take to the skies. Now the heroes must find the queens before they form new colonies, and spread the new, deadly species of insect all over the world.

Them! may well be one of the most influential movies on this list, jumpstarting the radioactive monster rope, delivering the first ever 'big bug' movie in a genre that is still popular, and featured one of the first ever strong female leads in horror cinema. Its influences can be felt in many popular films, scenes of characters wandering through the massive ant colony looking suspiciously like the hive in Aliens. Them! may have an incredibly silly premise, but it delivers everything straight faced and with a prevailing sense of dread. The audience is given little relief in the way of budding romances common in 50s horror films. The characters know they haven't the time for love. With none of the niceties to distract us, we are along for the ride with the characters as they travel all over the country to find those two queens before all is lost.