Pests are the tiny creatures that create not only diseases but also are responsible for financial loss, mental helth and social respect. Flies. mosquitoes, cockroaches are spreading diseases like dysentery, diarrhoea, typhoid, cholera and certain helminth infections, Zika virus, West Nile virus, Chikungunya virus, dengue, malaria Salmonellosis, Typhoid Fever, Cholera, Dysentery, Leprosy, Plague, Campylobacteriosis and Listeriosis. Bed bugs cause various skin diseases, allergies etc. Termites cause loss of building and gardening.