Continuity mistake: In an earlier scene as Melanie plays the piano and Cathy stands there look closely at the drapes on her left. In that scene the drapes were right up against the edge of the wall, now as Mitch checks the windows before the last attacks they're pushed back several feet. (00:57:30)
Continuity mistake: As Lydia walks up to Mr. Faucet's room, the hallway is dark except for the light coming through the door. The sunlight on the floor is much wider than the window of the door in front of her and there's no evidence of any light fixture above her or her hair would be lit up. (01:00:10)
Continuity mistake: After finding Mr. Faucet's body, Lydia gets back in her truck through the passenger side door. Notice that the window is rolled up and the side vent window is shut tight. Seconds later we see her inside the truck with the window rolled down and the vent window tilted open. (01:00:55)
Continuity mistake: At the party Melanie grabs a girl from the birds, but when they all run into the house Mitch is now carrying the same girl.
Audio problem: When the uptight mom asks how to get to San Francisco the guy at the bar that offers to take her lifts his glass up to take a drink and then we hear the overdub of the ice jangling in the glass. The jangling continues into the next shot after the glass is stationary and no longer near his lips. (01:22:10)
Continuity mistake: When Melanie is walking up to the counter in the bird shop she has a black purse in her hands. In one shot she is walking to the counter with her purse in her hands, but in the following shot, her purse is laying on the counter and is now taking off her gloves. (00:02:25)