Don't look too closely, or you will be hypnotized by the amazing cover of John Wyndham's The Midwich Cuckoos (1957) [the equally mesmerising back cover is available here].
In this book we have a quiet English village called Midwich. One night something descends over the town that puts everyone in it -- and every person who crosses over an invisible line surrounding the town -- to sleep. Odd, right? This lasts for about a day and then everyone wakes up. People try to put the "Dayout" behind them, although certain government types noticed that a strange large object landed near Midwich during the Dayout and are keeping tabs on the whole place just to see if anything develops.
After a bit, all the women of childbearing age in the village realize that they are simultaneously pregnant. Not such a big deal for the married ladies, but rather hard to explain for the spinsters, virgins, and wives whose husbands are off in the service. When the babies come out, they all look remarkably similar, and all have strange glowing eyes. They are dubbed The Children, and are grudgingly accepted into the village. Until they start using their mental powers to make people do their bidding!
As one of the philosophical leaders of the village puts it: "The important thing about the cuckoo is not how the egg got into the nest, nor why that nest was chosen; the real matter for concern comes after it has been hatched; what, in fact, it will attempt to do next. And that, whatever it may be, will be motivated by its instinct for survival, an instinct characterized chiefly by utter ruthlessness."
The odd thing about The Midwich Cuckoos is that it seems like a science fiction/horror type book, but it reads more like a philosophical novel exploring evolution, political science, human nature, and the English way of doing things. And that isn't a criticism -- I really enjoyed this book. It has a very satisfying ending and a nice pacing that never balances the philosophical with the mysterious.
However, I imagine that the film versions of the story (including The Bloodening, The Simpson's parody version of the film) focus a bit more on the freaky-scariness of The Children and a bit less on how stiff those English upper-lips can be. And now, for your enjoyment, the trailer for the 1960 movie The Village of the Damned, based on The Midwich Cuckoos. (In addition, John Carpenter remade this in 1995 and I can't wait to watch both versions.)