O’Fallon pest control services work very hard to stay ahead of the spiders, mice, ants, and cockroaches that assault homes in this part of the state. As the 7th largest city in the state, O’Fallon has a wide variety of housing. From single family dwellings, to duplexes, to apartment complexes, people live in varying proximities to each other. With the beautiful natural surroundings as well, there is plenty of nearby wildlife that contributes to the pest population.