Most flies (98%) caught in homes are house flies.
Because they carry and transmit typhoid fever, cholera, dysentery, pinworm, hookworm and tapeworm, house flies are regarded as a great threat to human health more than most other insects.
Organisms are picked up by flies from garbage, sewage, and other sources of filth and then transmitted on their mouthparts and body parts, through their feces and vomit onto food.
What you can do
Eliminate breeding grounds such as dung and garbage. Always cover garbage bins and compost heaps with tight fitting lids.
Remove pet manure, soiled bedding, straw, garbage and any other decaying matter.
Keep all Kitchen surfaces clean and dry and remove garbage from Kitchen as soon as you can.