Ticks (1993)

The plot depicts a group of illegal marijuana growers in Northern California who use steroids in order to increase the growth rate of marijuana. Unexpectedly, steroids are absorbed by lice and produce huge genetic mutations. Indirectly, these creatures bitten by big lice will hallucinate because of their venom attacks. At this time, a summer camp dedicated to leading children close to nature, unknowingly, was going here for outdoor activities. It was not until the children were bitten by vicious lice one after another that they realized the seriousness of the matter.