Moville Mysteries (2002)

Ouige Falls is having a serious problem with an unusual swarm of blood sucker mosquitos in this year. Then, a mysterious bug exterminator arrives in the city saying that he can stop the swarm. But when the exterminator comes to disinfect Mo's house, Mo realizes that the insectcide is not working, and the creepiest part, the exterminator only works at night! Will the exterminator be a some kind of vampire that is using the swarm to cover him, or there is more of one vampire in this story?