For fleas, concentrate on areas where pets most often rest. Spot treat those areas with a residual insecticide.
Flies are associated with sanitation. Clean surrounding conducive conditions. Flies can also originate from agricultural farms and seek conducive breeding conditions inside structures.
Ticks usually enter premises via pets or by hitchhiking on clothing. Treat periphery with a liquid, as one would for any occasional invader.
— Dr. Reid Ipser, Director of Technical Services, Nisus Corp.