Why do flies like poop? (SURPRISING Answer!)

As summers are approaching, many of us are getting worried about how to deal with the attack of flies at home. If you don’t want to run the AC all the time and allow natural sunlight and air to enter your home, you will need to keep your windows open during the daytime. Often along with the fresh air and sunlight, house flies to enter our homes.


They will roam around in every corner of the house looking for food items and often will be circling around the garbage bin or any rotting item which is left outside. If you have pets at home and they have pooed in the area, within a few minutes you will find the poop covered with houseflies or blowflies (Calliphoridae). If there is a leak in your drains, you might also see a lot of flies in this area. In this article, we will look for the reasons why flies get attracted to the excreta of mammals and other rotting items.

Why do flies like poop?

Entomologists have done an extensive research to find the reasons why flies are attracted to animal excreta and other substances. Let’s understand the reasons here-

1. Odors

The odor of poop is extremely appealing to flies. If the flies move upwind towards the source of the odor, the entomologists rate that odor as attractive. When it comes to the excreta of other animals, the rating showed a strong affinity towards the source of the odor.

If the flies move away from the source of the odor, it is considered a deterrent. Entomologists tried multiple species of flies and they were all attracted to the smell of feces.

Since flies taste with their feet, they sit on an item to check it first. Their receptors, or chemonsensilla, are situated in their feet. Hence the odor of any type of excreta attracts them first and they use their receptors to taste the food (in this case excreta) first and then consume it.

2. It is food for the fly

Flies extract nutrients from the excreta of animals. Since it was originally food that was digested by the animal, the animal’s body kept the nutrients that it required and discarded the rest. However, it still contains many fats, proteins, vitamins, fiber, cellulose, and minerals that the flies can feed on. The excreta even contain many types of bacteria which might be dead or alive, however, are important for the survival of flies.

3. Reproductive needs

Stable flies and house flies lay their eggs in the excreta of animals as it is a hot and safe environment. We all know that flies have four stages in their life cycle- egg, larva, pupa, and adult. They often allow the egg to go through these stages by extracting nutrients in the excreta of the animal and becoming an adult while being nestled in the poop. The flies need to ensure that the moment the egg bursts and the larva comes out, it gets nutrition from the animal excreta.

Safeguard your family

As flies sit on feces, carcasses of dead animals, garbage, drains and all types of rotting food items, they spread many types of dangers. If flies enter your home, you need to immediately get rid of them. Do not allow them to sit on your food items or even utensils. They can spread harmful bacteria to anyone who consumes that food or eats on that plate.

Whenever flies sit anywhere, they leave their own excreta too. Mostly it is not visible to naked eyes, however over a period of time, if you observe your windowsills closely, you will see black dots there. Those are piles of fly poop that got accumulated over a period of time and hence is visible to naked eyes now.

You might find such piles of fly poop on the top of your refrigerators, kitchen cupboards, near sinks, drains, etc. A lot of flies in an area can indicate a problem. Plumbers often get called out to fix drains after people notice a lot of flies flying around. You should examine the home when you see a lot of flies.

Flies also tend to vomit when they sit on food items spreading more bacteria and other micro-organisms. Hence, do not keep your garbage can in the open and cover all the food items which are left in the open.

Fun facts

Now since we know that flies are attracted to the excreta of dogs, cats, horses, cows, human beings, etc. if you are wondering whether they are attracted to their own poop? Well, the answer is ‘’no’’. Flies gather nutrients from the excreta of other animals and even the droppings of birds as their bodies have discarded them; however, the mass still contains nutrients. However, what the flies’ bodies have discarded does not have any nutritional value to them.

We have discussed why flies rub their hands here.


Flies play a huge role in the ecosystem and the food chain. We might find them as annoying creatures buzzing around, however, they are responsible for the pollination of many types of farm produce. So next time, before killing a fly, consider opening the windows and letting it out.

It is a good idea to get pest control done in your home if it is frequently infested with flies. It is a high possibility that there are dead mice, lizards, and other smaller animals trapped between the drywalls or under the furniture. Basements, garages, and storerooms which are not cleaned on a regular basis often become home to insects and pests.

Hence along with keeping the drains around your home clean, it is important to hire professional cleaners to get these areas clean. Cobwebs attract insects and often the carcasses of dead insects become the feeding and breeding grounds for flies. Have a happy fly-free summer!!

Flies do have their purpose though!