
Continuity mistake: In the scene where the spiders are starting to attack the city, it shows the guy in the barber shop closing up. He shuts the blinds then his friend gets attacked by the spiders, then he goes back out in front and the blinds are still open. (00:51:00)
Answer: Both! The owner of the spider farm was feeding the spiders bugs from the water that had the chemical spill in it. The bugs were contaminated with the chemical, thus contaminating the spiders. Note: The man who owned the spider farm had no idea about the contaminated water.
SAZOO1975