Summary: A whole town gets attacked by gigantic weird and violent creatures (spiders and insects).
Production date: I'm not really sure, but not that old. Probably something in between 2004 and 2009.
Scenes I remember:
A whole town gets haunted by giant insects, including spiders, weird scary creatures. They all hide in a supermarket, many die and many survive.
A crazy woman was reading the Old Testament mentioned something about children sacrifice and she wanted to kill a young boy there.
The young boy is supposed to be the son of a the protagonist (probably) who will later be protected by his father.
After the father puts his family in the car, he gets completely hopeless, stuck in the middle of nowhere and surrounded by the weird violent creatures who will torture and eat his family, he takes the gun and shoots his family. A few seconds later, rescuers looking like the US Marines come to rescue the town. They are pictured evacuating the area and spreading some poison to the insects.
And that's how it ended: very sad, and disturbing.
The moral was obviously, never ever give up.
Anyone can help identify this movie?