Swarmed

Kent Horvath (Michael Shanks) is a scientist, trying to invent a new pesticide, specifically for yellow jacket wasps. He tests its effectiveness out on eight yellow jackets, finding that it successfully kills six, but the two who survived now have extremely high pheromone levels, resulting in increased aggression. That night, the janitor (John Baktins) accidentally releases them, and they both attack, killing him. They find his body the next morning, along with one of the wasps, with the other one nowhere to be found.