Bug ,

Agnes (Ashley Judd, left) and R.C. (Lynn Collins, right) try to calm Peter Evans (Michael Shannon), who thinks he's being swarmed by insects in Bug.

This review might make you itch. The movie might, too, causing wiggly sensations on the scalp, the neck and that damp, vulnerable spot behind the knee so popular with mosquitoes.
There, feel that?

On your shoulder. That's William Friedkin back there, biting away with the single-minded hunger of a parasite. He never shows the bugs in Bug (except for one flash of an image), but they're much discussed, often heard and thoroughly obsessed about in this atmospheric-claustrophobic-paranoiac entymological fever dream.

We hear about crickets, fruit flies, spiders, lice, ticks and other exoskeletal uglies, but aphids are the worst. Whether real or imagined, they spill a lot of blood in Bug, the latest proof that Friedkin's legendary output (The Exorcist) hasn't quite finished with unseen demons that take possession and burrow deep, body and soul.
Among the possessed is Aggie (Ashley Judd), a sad case of a waitress living in a run-down motel in Someplace, Oklahoma.

(Without motels, would there be horror films?) Bug's opening image is a quick flash-forward to a gory corpse in a foil-wrapped room, a ghoulish tableau that's explained in the second hour and repeated, just for fun, after the closing credits.
From there we move into the dilapidated motel.

It's night; it's lonely; the soundtrack tinkles with a few bars of left-hand piano.