Kingdom of the Spiders
Like Day of the Animals listed above, Kingdom of the Spiders is a 1970s wildlife revenge film. But in this one, tarantulas form armies and swarm people. William Shatner (from Star Trek) plays Rack Hansen, an Arizona veterinarian trying to figure out why some farm animals are suddenly dropping dead. But the spiders eventually move on to people.
If insects were ever out to get people in real life… we can’t blame them. The overuse of insecticides and rapid habitat loss has greatly depleted bug populations all over the U.S., and the world. Some bugs are invasive and their populations should be controlled, but native insects are important for ecological diversity and health.