Yah, I thought "Gender social-political statement cleverly disguised as action horror scifi" about covered it, to put in succinctly.
I am disgusted by the many superficial comments about how this is Joe Dante's work, or that its a ripoff of "28 Days Later" ???? I mean, BUNCH OF MORONS! This is an accurate adaptation of a James Tiptree Jr. story which was written before the "28 Days Later" maker was even born! Literally. Dante should get kudos for almost exactly following the story. James Tiptree Jr. later revealed that she was actually Alice Sheldon, a 63 year old college psychology professor, who would later commit a murder-suicide with her husband 13 years her senior, at age 71.
The story is in line with James Tiptree Jr.'s gender themed work. What's the easiest, cheapest way to take over Earth but still get rid of those pesky humans? You disturb the reproductive cycle, of course, just as humans have done with insects, so the humans get rid of themselves. And not via war, like the west v the Muslims or Americans v Russians/Chinese or even cowboys v Indians, but simply via Man vs Woman. That the Man is chosen to be the instrument of death rather than woman, is only seemingly connected to Tiptrees AKA Sheldons political beliefs but is heavily based in actual scientific fact (and simple common sense): men are far more easily led towards violence than women ....
The Melancholic Alcoholic.