Goofs

When alien Tom almost hits the other car, the other driver complains that Tom didn't have his lights on. The shots reveal that is clearly daylight.

As Marge leaves Captain Collins' office after her second plea for help, the shadow of dollying camera equipment is visible on the wall and floor.

The plot assumes that men who have recently had children have to be human, but they may have been possessed after the conception.

After the newlyweds depart the church, they are driving down a country road. Just as they are about to pass a mysterious alien figure, the shadow of a boom mic can be briefly seen on the road as the camera traverses with the motion of the vehicle.

About 16 minutes into the film, when Bill and Marge are talking outside in the yard, the boom mic can briefly be seen reflected in the window glass.

Alien Tom somehow knows how to drive a car but, Marge has to show him how to turn on the lights.

When they are taken over by the aliens, the drinking buddies stop consuming alcohol. It is never explained why alien Tom would take up smoking.