There were no windows visible in the examining rooms where Jennifer was being treated - however, lightning flashes were visible from there.
In the beginning credits an actor is listed as "Matthew Jordon", while in the end credits he's listed as "Matthew Austin Jordan".
When Charlie shows up at the hospital near the end. He blasts away at the Mansquito with a 9mm semi-automatic pistol. But when the Mansquito impales him and lifts him up, he shoots himself in the foot and is holding a silver revolver.
Since only female mosquitoes bite people and drink blood, the creature Ray Eriksson became should not have been feeding on humans. Male mosquitoes feed on plant juices, so maybe the Eriksson creature should have gone around attacking trees.
The wings that the creature sprouted were far too small to lift it off the ground.
It is entirely against procedure in any police department to seat a civilian in the front seat of a squad car, in order to prevent what Jennifer did - steal it.
When Tom is fighting with Eric he cuts one of his wings in half but in the next scene it's completely intact.
When Jennifer is checking out her reflection in the lab, she lifts her hair on the left side, but, in the reflection in the glass, it shows her lifting the hair on the right side.